FiTech or Holley Sniper on 1950 331 ?

[First]

Has anyone switched out there carb for an EFI system?
I'm thinking of getting rid of my 2bbl manifold for a "52" 4bbl manifold and installing either the FITECH or Holley Sniper EFI system.
I already did the 12v conversion, electronic ignition and added power windows.
Any thoughts?

[James Landi]

That Holley innovation seems so attractive (except for the price).  I've owned several big block marine engines with Holley carbs... they make a good, durable and elegantly simply product.  Happy day,  James

[Skwerly62]

I was looking at the same for my 60. Guaranteed you will need to install an electric fuel pump/pressure regulator. I would just jump in with both feet and get their ‘kit’ with carb, pump, lines, etc. Definitely give tech service a call to make sure they recommend one that works for a Caddy. Good luck!

[35-709]

EFI in a 1950?  Have you converted to 12 volts, or are you going to?

[INTMD8]

I've been looking at these systems for my 69 Charger. Have not come to a conclusion yet. All the systems seem pretty decent. I put more importance on being able to access the parameters via laptop and don't care so much about self learning which eliminates some of  Fitech's offerings. 

Only doing it because of dual 4 barrel.   

Probably wouldn't bother if it was a single carb.  (have no plans on running efi on my 59 with single original carb for example).

[INTMD8]

I just spoke with Fitech, they won't send me a copy of the tuning software or even screen shots to see what it looks like.

Just kept repeating  "most people don't need it".   For that reason I won't consider it. 

Holley sniper is what I would go with but they don't have the dual 4 barrel setup ready yet.

[TJ Hopland]

I have an FiTech Go 600 on my 73 Eldo.  Ran it all last summer and part of the previous summer so not tons of miles yet.  Before that I had Megasquirt driving an old Holley Projection 2bbl TBI.   I think I had the Megasquirt for 5+ years.

The Megasquirt was far from a plug and play setup so if forces you to learn and understand what is going on.   Often times the hardware is sold in kit form and the software is open source which means users can modify it.   When I did mine there was a very active forum and community.  You could do the hardware for $300 which was quite a savings when the complete kits were $3500+ at the time and not as configurable.   When I first did it I enjoyed learning and tinkering all the time.  I got it so it ran pretty good and didn't really touch it for 2 or 3 years.   The car started to develop a stumble and occasional backfire that progressively got worse.  I blamed the EFI and didn't really feel like refreshing my memory and skills on that system and had been reading a lot about the FiTech that had been out about a year at the time.   There were rumors of the Holley Sniper at the time but nothing confirmed so the next closest system was still in the $2500 range.    Ended up with enough extra cash mid summer so decided to do it.

With my previous experience and already having some of the bits already done on the car from the previous system it only took me a few hours to make the swap and it pretty much started first try and was drivable.   After a couple tweaks and driving around the neighborhood for a couple hours which luckily had a couple block stretch with a 50 mph speed limit I could gun it on it was running good except for a few hints of the stumble and backfire.  That was pretty much proof that it was the ignition systems fault in the first place.   Ignition was a HEI that I had changed the weights and springs on and added a stop to the vacuum.  Basically the problem was those mods got the rotor phasing off so under some conditions the spark was having to jump too far or jumped to the wrong terminal especially after some miles and humidity in the cap. 

Ignition problem was eventually solved by letting the EFI run the timing via a modified HEI which was the original goal even back with the Megasquirt.  That did introduce a few bugs that took some time to sort out but I eventually got them and didn't have to mess with ignition at all last summer.   Last summers issues and modification were to the fuel delivery system which I chose what the DIY people called a swirl pot which is basically a small tank up front that is fed by the mechanical pump and houses a typical in tank high pressure pump.   My original mounting location was behind the radiator shroud which I thought would not be an especially hot spot since it should not get direct hot flow from the radiator but I was wrong.  It got hot enough that it would vapor lock even with the return flow.   My fix which I did fairly late in the summer was to re arrange things so its next to the radiator.   So far so good but I didn't have it out on any real hot days after the change.

Both systems come with a little handheld programming computer.  I know for sure FiTech doesn't need it hooked up once you get it programmed but you can leave it connected and have it display custom gauges if you want.   I'm pretty sure Sniper is the same way.  I know the bigger Holley systems work like that.   This is what you use to do the basic simple setup that usually gets it running.   FiTech then has an advanced page you can further tweak the ranges and such which I have found to be completely adequate to further dial things in. 

Both Holley and FiTech have options so you can do laptop tuning but you really need to understand what you are doing and be ready to commit to the time it will take to get that deep.   Also be warned that many people become obsessed and try to tune out every possible minute glitch real and imagined.   FiTech I think that comes with the power adder packages.  Holley I think you just have to buy the software and special cable.   Megasquirt was laptop only tuning and I found it to be a hassle.  I don't know how many times laptop slid and banged into the door or hit the floor usually 'crashing' the ECU when it happened sometimes causing the car to stall.  I hope that FiTech and Holley are more stable than that but for a street car I just don't see a need.   If you have a track car and an assistant in the passenger seat to watch and do things with the computer than ya its a great idea.


My experience is mostly FiTech but I started helping a friend with his Holley late last summer and will likely be on it this spring again.   I am staying somewhat current on a couple EFI forums where there are several people running both FiTech and Sniper systems so I do have some knowledge of the Holley which will likely come in handy this spring.   FiTech was a runaway success so much so that they were completely overwhelmed in every way so it was hard to get product and almost impossible to get any sort of support.  That success forced Holley to rush the Sniper to market and I suspect also lowered its price.   Sounds like they have got a little better but the general buzz on the forums is they still have pretty bad customer service.   Holley support can be hit and miss but people never complain or rant about it like they still do with FiTech.  I think I made 3 or 4 support inquires with FiTech and only got a useless response to one.   If I had it to do over or did another one I think I would go with Holley.     

First issue I see and can totally understand from my own experience is expecting the EFI to fix and engine with issues.  In my case it was an ignition system problem.   I read lots of others with  poorly designed and  built or worn out engines that didn't run with a carb that somehow expect EFI to solve that.   It may be able to mask issues better than a carb can but it won't solve them.   

Second huge issue is fuel delivery.   Those that are lucky enough to have a car that you can buy an aftermarket made for EFI tank with an in tank pump seem to almost never have any issues at all.  EVERYONE else including me that could not or did not go that route has had issues that took a while to narrow down to basically vapor lock or a priming starvation issue.  I think I improved my system quite a bit but still don't think it would be as good as an in take setup.  Luckily for me having a 70's GM car there are some other tanks that appear pretty close available I would just have to fabricate the mounts.  We will see what happens this summer, maybe it won't be a concern with my latest mods. 

Third is ignition.  Ultimately you likely want to take advantage of having the EFI system do the timing control but that introduces a lot of variables you just don't need on your initial setup.   Most people have a working ignition system now and even if its points you can leave it alone and concentrate on getting the fuel part working.  Once you got that you can then do the conversion to get timing control if you want to.     

[TJ Hopland]

If anyone has questions about specific aspects of these systems I will be happy to try and answer them.

If anyone else has hands on experience I would love to hear their story and take on things too.   

[Jay Friedman]

Some years back a friend installed fuel injection on a '49 with a 331 engine, a 2 barrel manifold and 6 volts.  As I remember, sensors had to be installed in the cooling and exhaust systems and possibly elsewhere which required some fabrication.  Also, he had to fabricate a plate on the throttle body to accommodate the Hydramatic kickdown rod and the accelerator linkage.  Finally, the system had a computer "brain" under the dash with extensive wiring which required that the electrics be switched to 12 volts.   The car did start and run a bit better, but probably not so much better that it was worth the expense and effort. 

Therefore, I would like to respectfully ask what problems are you having with your engine's current performance, since a stock 331 can be made to run very well with lots of power on the Carter WCD 2 barrel carb?

[TJ Hopland]

Sniper and FiTech GO series claims to fame are $1000 price point, self tuning (which you can limit and or disable if you want), and most sensors and ECU are contained inside the throttle body.   

I'm pretty sure Sniper is same as FiTech in that external sensors are coolant temp and O2 (exhaust).   Both have wires with connectors coming off the throttle body.    There is then another harness that has like 8 wires.   That one has your always live battery +,  key on, tach / distributor pickup, fuel pump control,  and a couple optional auxiliary wires usually used for electric fans and maybe a nitrous or turbo setup.  That's it.     Older systems MAP was either external or you had to run a hose to the ECU.  Ambient temp, incoming air temp, TPS, IAC, injectors, were all things that needed to connect back to the ECU which they usually recommended you mount in the cab so it often was a decent size harness you had to cut and feed trough a hole in the firewall.

I think all the systems now include a bung on a plate and some hose clamps so if you don't have a way to get a bung welded into your exhaust for the sensor you can just drill a hole and clamp it.    The sensors are now all heated so you don't have to get them as close as possible to the engine.  Only 'catch' is they need to be mounted so condensation will drip off them, not settle into them.  Basically pointed down, not up.

Linkage really depends on what sort of setup you are running.  They are basically what has become the standard aftermarket carb setup so for the common combos you can buy brackets for cables to deal with all the popular transmissions and pedal cable setups.   As expected pretty much anything Cadillac doesn't qualify as popular.   My intake is modified so other than the bottom of the arm hitting a runner on the intake I could direct mount it.   I didn't need the bottom of the arm anyway so I could have cut it off but I decided to use a spacer which I already had from my previous setup.   I did make a custom pin/shaft/bolt sort of thing so I could hook my stock pedal cable up and the stock cruise chain.

The linkage reminds me of another common complaint,   throttle too responsive with stock pedals.   Apparently the geometry is different between aftermarket and stock so what you need 9 times out of 10 to get a stock response is to extend the arm a bit.   People try screwing around with the return springs which often causes stuck on situations.   
FiTech there is a hole that maybe has some sort of bolt or pin available to fit but I made one since I also wanted it to work for the cruise.   I made it out of a 5/16 or 3/8 bolt on my lathe but you could also do it with a file in a vice if you had to.   If I had taken more time to search places like Summit and had the patience to wait to have something shipped I could have likely found something that would work there too.    The Holley for some reason doesn't have another hole in their arm so on those people fabricate a little extension.   We are only talking about maybe 3/8 of an inch higher so its not a huge change but it makes a 300% difference in the response.           

[The Tassie Devil(le)]

I use the best thing next to Fuel Injection.   A Predator Carby.   No hassles with Injectors, high pressure fuel pumps, or electronics.

Got one on my Eldo.   More economic than the original Rochester, and quicker response.   But then, who in a Cadillac wants quick response, and fuel economy.

Bruce.

[TJ Hopland]

Injectors tend to be pretty reliable and easy to deal with if you have to but like I mentioned in my long reply the high pressure fuel part is a lot easier said than done in many cases and seems to be the source issues for many people.   

That was one reason I did the old Holley system to start with,  it was like the GM TBI systems and only ran around 13 PSI,   much easier to deal with on just about every level. 

[First]

Wow, many responses to this thread!
It looks like I have some reading to do.
Yes, I already did the 12v conversion, electronic ignition and added power windows.
I am in contact with a Holley tech regarding there Sniper system. 
I believe the FiTech system has a small holding tank that holds fuel, pressurizes and feeds fuel to the injectors and the Holley system uses an inline or intank fuel pump?
I just got my 4bbl intake today so now I know the bolt pattern

[bcroe]

Lots of good info above, I will add some of my own experiences. 

Always I wonder, why go to all that complication and trouble on
an old system that is working well?  Sure engines with features
like boost or variable cams must have it.  It is a necessity so that
all the emissions equipment can work together to meet recent
emissions requirements.  Your current engine isn't running right,
don't expect EFI to be a magic cure all. 

About 1990 I put a FAST throttle body, MAF system on a 403,
which I drove daily, hard, and far.  What would happen after it
sat outside all night at 20 deg F below zero?  To my amazement,
it started up and ran like it was spring.  The system adapted well
to air and engine temp, and would have run far better than several
carbs I had taken to 14,000 feet on Pikes Peak.  My question is,
are the above situations what you plan for your EFI conversion? 
EFI will contribute little to a fair weather trip to the store. 

There seems to be an impression that EFI is just a simple bolt on
conversion, drive it away.  The first thing to understand, is what are
the system features?  There is port injection and throttle body injection. 
Peak and Hold, or saturated injectors.  MAF, or MAP, or (please no)
throttle position fuel control.  My early MAF system used a Mass Air
Flow sensor, which must be ducted so that essentially all air entering
the engine must flow through it.  It ignores the pressure and the temp,
and figures out the exact weight of air entering.  Then it can match the
proper quantity of fuel to the air.  The beauty of this approach, nearly
universal in OEM systems, is that it is close to plug and play. 

Another approach is to sense the Manifold Absolute Pressure. 
If the displacement and flow of the engine are known, its possible
then to ESTIMATE the fuel required.  Air temperature must be known
to get a reasonably accurate estimate.  These systems are simpler to
install, but then must be taught how your engine flows, often a long
(think months), tedious process. 

One approach is to just adjust fuel to the measured angle of the throttle. 
This has been made to work on the track, where idle and WOT are the
only considerations.  DO NOT even think about it in a street car. 

Then there is the ignition.  Modern EFI completely maps out spark
advance, along with temp compensation and knock sensor input. 
MANY of the add on EFI systems completely ignore this function.  If
you want it, it isn't too bad with an electronic ignition.  Hard to imagine
with points.  At the very least, its a complicated set of information than
must be entered for YOUR engine. 

A good EFI has a lot of feedback loops.  OX sensor, idle speed, knock
sensor, more.  OEM actually takes this info and builds up a correction
chart to the factory info, continuously adapting to variations of your
particular engine.  Earlier add on EFI had no such feature.  Now there
are some self learning systems, the jury is still out on them. 

Certainly EFI will require rework of the fuel system.  An electric pump
should be located in the fuel, either in your tank, or in another reserve
tank you add.  Wiring, control, and a return line will be needed.  Some
basic level metal fab work is inevitable. 

My experience is you really need more instrumentation for EFI, and
its not a bad idea on a carb too.  A Wide Band OX sensor needs to
read out your exhaust gases, and an electric fuel pressure gauge can
help sort out things.  Both of these have reached a very practical level
for consumers in the last dozen years, not so when I first tried EFI. 
Check also what logging features your EFI system may offer, mine
failed to deliver the claims. 

EFI systems are pretty much digitally controlled now, I have tried 3
that were analog.  I set up system emulations on my bench which
could set up any situation, to learn the systems.  The digital systems
I tried all had software bugs, that would be much harder to detect with
an engine on the road.  The mfrs generally didn't seem anxious to fix
these bugs, one suggested they might sell me a software update (to the
defective software they had provided) for $300. 

Another problem was using an add on ECU to run my existing port
injectors.  It managed to convert from my batch injection, to sequential
injection.  BUT it claimed the ability to drive either saturated, or my
peak and hold injectors.  My Oscope showed that the power driving my
injectors was entirely unacceptable. 

I don't know how EFI would be applied to a pure 6V car.  Even the
injectors require more voltage than that to operate. 

Add on EFI can work very well, but I have seen some that never were really
right.  If you are looking for a challenge, and all this sounds like fun,
have at it.  Make sure you know what you are doing.  Bruce Roe

[bcroe]

Something else to check, is the throttle body operation.  Early EFI used
a 2 barrel, so to be large enough, it was like opening the secondaries
on a Q jet.  This would consistently spin my 79 Eldo tires.  Then they
tried using an egg shaped crank for the throttle cable, better.  Best
is probably a 4 barrel progressive linkage, like a carb.  They exist for
a price.  Bruce Roe

[TJ Hopland]

In the last 5 years the aftermarket EFI game has completely changed.  I started being interested in it in the early 90's but didn't get serious till maybe 10 years ago.   Once I got mine running decent I was content and didn't really pay that close attention till a couple years ago and was amazed when I started reading more than just the ads and TV shows, some of it was actually true! 

FAST may have been the first to use what were basically high pressure port injectors in a throttle body.   Most of the other people including Holley until fairly recently were using the low pressure injector pods most commonly associated with GM.   I think Holley actually made the early Chrysler factory EFI systems.  GM was the only one that stuck with the TBI's.  When everyone else had completely abandoned them in favor of multi port injection they decided to put it on every truck they built which was 87-95.

Everything now has feedback from several sensors and they all have wideband o2.   I don't think any of the throttle body systems are using MAF but most of the systems where you are buying a new intake assembly use them which is awesome as long as you are working on a Chev or a select few Ford and Chrysler motors that they make them for.

All the current throttle body systems are 4bbl with 4 or 8 injectors.   Some I think are progressive, FiTech Go isn't, I don't think the Sniper is but I could be wrong.   No one makes a 2bbl but rumor is Holley is going to have one soon.   Its intended for the guys running sub 300 hp inline engines which believe it or not seem to be gaining popularity.  When I had my 6 cylinder Mustang at shows I had way more people asking questions and looking under the hood than the V8 guys did.   The original Holley I had was a 2bbl and had something like 55mm bores, I think the QJ secondaries were only 50.  Once I extended the throttle arm I didn't have any issues with the response.  Before I did that it was hard to not spin the tires pulling out your garage and mine was in a 73, not the much lighter 79 like Bruce had.   

As far as I know all the systems can run off any existing distributor, it just takes the classic tach signal so it knows how fast the engine is turning.  Distributor and timing work the way they always did.    Many of the systems now including Sniper and Go600 and up can be set to take a magnetic tach signal which was the most common method for the factory electronic ignitions.  You either buy a made for EFI timing control distributor or modify an original by locking the weights and vacuum down.   Pickup sends the 'tach' signal to the computer which then can do the timing and direct drive the coil so you don't even need a module of any sort in the distributor.   The big confusion and issues with this route is something called phasing.  Its easy if you can wrap your brain around the concept but the manuals do a terrible job of explaining it not to mention different brands using different terminology and trying to sway you to their stuff which doesn't just plug n play most of the time either.         

[TJ Hopland]

I forgot about the fuel tank pump subject....

The fuel tank thing you see often mentioned related to FiTech is something they call their Fuel Command Center.   If anyone has got it to work reliably they never talk about it.   When I started seriously considering FiTech and saw they offered that Command Center I figured I would just get theirs because it must be designed to work perfectly with their systems right?   Then I started reading reviews and forums,  glad I did because I think I saved myself a lot of hassle. 

There are 2 basic concepts when it comes to these things.   One is simple, one is complicated for no apparent reason and seems to have no advantages at all.     The simple version is what I bought and I liked because it was the way the DIY people were doing them when I first got into EFI.   

Both versions are a small tank, maybe a couple quarts, that contains a normal in tank electric high pressure fuel pump.  Its a small volume so no issues for the electric pump pickup going around corners and such.  If the main tank sucks some air going around a corner its just like the float bowl in a carb acting as a reserve so you don't starve your main pump while its re priming which is easy to do for a mechanical pump.   

The simple ones have 4 ports.  One port is the outlet direct from the pump, no regulator.   The other 3 ports are just open into the tank.   One of those ports gets connected to the low pressure usually mechanical fuel pump that pumps fuel into the tank.   Another port is the return from your external inline regulator or the regulator at the end of your fuel rail.   The last port is the return line back to the main tank.   Pretty simple any fuel not used at the engine comes back to this tank.   Any excess fuel from the mechanical pump or air gets pushed back to the main tank.  This is a great concept because it keeps things flowing which is good for keeping cool and will also send any air that got in for any reason back to the main tank where it doesn't cause any problems.   DIY and some types of racers have been doing this for years.  I wanted to do it originally but at the time you could not buy such a thing you had to make it yourself and I didn't have the welding and brazing skills required to do it properly.    The one I bought was the older version from this guy that has been around for a long time and has a great reputation.  http://www.robbmcperformance.com/products/powersurge.html    If you call or email you talk to Robb himself.  Not sure if its a one man show or if he just likes to deal direct with the people.   FiTech now has a similar product I think they call the Hyperfuel G Surge.   No one on the forums seems to have tried one since they had such a bad rep with the Command Center.

The complex for no apparent reason version is similar.   FiTech has their Fuel Command Center and Edelbrock has one too that cost like $800.   There are 2 big differences with those other than they cost more.   One difference is that they have an internal regulator so you can run 'return less' from your fuel rail.   This seems to work fine for the OE folks that have complete control over every single system on the car but often seems to be flaky in the aftermarket where there are a lot more variables.   The other difference and the one that seems to cause the most serious issues is that last port being called a 'vapor return'.   

Where the vapor part comes in is these have a float, needle, and seat like a carb bowl so in theory they are only 3/4 full.   That last 1/4 is in theory just vapor.   The vapor port has some sort of a check ball in it that is only supposed to let vapor out or one way or some such thing.   They both say that you absolutely have to connect that back to the tank, you should never ever leave it open or run a hose to the ground.

The way I see it and based on what others experiences have been I think I am right that its a flawed design.   Lets say you are at idle or barely moving.   What happens?   Float is going to let little to no fresh COOL fuel into the little tank.   Electric pump is working away full speed pumping how ever many gallons per hour it was designed for if you are using it or not. Doing that is creating heat in the pump motor itself and is either pumping fuel around in circles internally or up through the fuel rails on top of the hot engine and then back to the tank getting hotter with each pass.  Very quickly even on a mild day fuel boils.  When it boils it quickly overwhelms the return valve and end up pushing boiling liquid fuel into the return line back to the tank.  At this point your engine likely stalled or is barely running because boiling fuel just doesn't pump well or inject properly.   If you didn't follow the instructions and run that 'vent' back to the tank you have an additional possible problem that you are squirting boiling fuel all over under your hood. 

So you sit with the hood up thinking what have I gained here?   I had this same issue with the carb and it didn't cost me as much.   You then finally figure it cooled down enough that you should be able to start it again and continue.   It does eventually start and smooth out and seems ok but then starts to stumble and starve.  While you are again sitting on the side of the road you pull out your phone and look to see if anyone else had this problem and find out its very common.   What happened is the vent can no longer vent properly because of the liquid fuel sitting in the lines.   You have to disconnect and blow the fuel out of the line one way or another before it will run right again or at least till it gets warm again and the whole process starts again. 

I just don't get why the float concept?  If you didn't have to run / use a return line back to the tank I could see it being and advantage but since you still need that whats the point?   It cost more, has more moving parts to fail, and greatly increases your chances of vapor lock which is likely one if the reasons you went to EFI in the first place. 

Like I mentioned earlier the best chance of these types of systems working is to mount them in as cool a place as possible.   Back of the car is no good because you are too far from the mechanical pump and didn't want to have to run the high pressure lines front to back in the first place.   So this leaves you with next to or in some cars in front of the radiator.   A lot of the older cars have lots of room on either side of the radiator or even in the fender well so that seems to be the best option.   Anywhere that has any chance of catching any hot air from the radiator or near exhaust is just going to cause problems as I found out. 

[bcroe]

Oh yea, your EFI may not fire all the injectors at the same time.  In
sequential injection (requires port injectors) each injector is fired
shortly after that cylinder intake valve closes.  If you get the phasing
right.  To do that requires a cam sensor or the equivalent that keeps
track of every 2 revolutions, one combustion cycle.  The sensor might
be in the distributor, or off a plug wire (not for coil packs). 

The Cad 79 system used 2 banks of 4 port injectors each, alternately
fired on alternate crank revolutions by special HEI reed switches. 

A variation is alternately firing the throttle body injector(s).  Again
the phasing needs to be right, my FIRST did it off a plug wire.  The
crudest way is to just fire every injector every revolution, not my
choice.  Bruce Roe

[TJ Hopland]

Interesting question about how they are firing a 4 or 8 injector throttle body these days.   I don't know.  On mine I hear more clicks than one per turn so I suspect its a batch fire but not for phasing purposes, more for keeping the rail pressure more even.  If you fired all 4 at once you would drop the rail pressure momentarily.  Not a problem if there is enough time before you need to fire again but if you needed to fire again soon even if your next pulse was the same length you would not get as much fuel because the pressure was still recovering.   The 8 injector versions I have no idea, it would add complexity and expense to fire them all separately so do they do 2 batches or 4?  With a dual quad setup the second unit slaves to the first so they could offset them but when all 8 are in the same TB I don't know.   


I should backtrack slightly on the fuel pump subject and explain there are basically 3 options for getting fuel to your fuel rail.

Option 1 is what I described above, usually called a surge tank.  You keep your stock tank, stock line from tank to mechanical pump, and mechanical pump.  That then feeds this tank which contains the high pressure electric pump. 

Option 2 is an inline / frame pump.   Downsides to these are they are often noisy.  Often difficult to mount in the ideal position so they have the best chance priming.   Often are being used with a tank with no baffles so chances of loosing prime if you are below a 1/4 are great.   All of these things lead to short pump life and reliability issues.

Option 3 which seems to be the best but may not always be practical on older less popular makes and models which is why there is option 1 and 2 and that is an in tank pump.   There is a reason almost all the OE's did and still do it that way,  it just works. 

As far as I have seen most of the EFI people offer different levels of kits.   The basic kits don't have any sort of fuel pump, its all up to you.   They then offer deluxe or master kits or bundles that include all the above options.    If you had a Chevelle or a Mustang I think its a no brainier, get the bundle with the new baffled tank and internal pump.  If they don't have a tank for your car then you have some fabrication to do or some compromises to make.    One interesting possibility available from several manufactures is a tank pump retrofit kit.   Some even include a baffle sort of thing that should help the below 1/4 tank sloshing issue. 

My Megasquirt / Holley combo I ran for years used an inline pump I mounted to the side/bottom of the stock tank.  I would often get hiccups if I let it get below 1/4.   I think the reason I just had hiccups was it was a low pressure system so it was easier for the pump to re prime and was way more tolerant of pressure variants at the injectors.  When your full pressure is 13 psi and to drops to 10 you barely notice.   When you are supposed to be at 60 and you drop to 40 you may not stay running.     

[Caddy Wizard]

Some years back a friend installed fuel injection on a '49 with a 331 engine, a 2 barrel manifold and 6 volts.  As I remember, sensors had to be installed in the cooling and exhaust systems and possibly elsewhere which required some fabrication.  Also, he had to fabricate a plate on the throttle body to accommodate the Hydramatic kickdown rod and the accelerator linkage.  Finally, the system had a computer "brain" under the dash with extensive wiring which required that the electrics be switched to 12 volts.   The car did start and run a bit better, but probably not so much better that it was worth the expense and effort. 

I am the guy who installed EFI on a 1949 331. It performed extremely well.  Of course, it needed 12v.  It was a throttle body system, based on GM throttle body and injectors.  Once installed, it performed flawlessly.  It required a few sensors (simple, really) including an O2 sensor in the downpipe of the exhaust.  Brain went behind the dash, but now you can buy them with a brain integrated into the throttle body.  Trickiest things to do were to modify the air cleaner to fit on the TBI unit and look good and to add a little plate to the side of the throttle linkage to allow the HydraMatic's "TV" rod to be actuated in exactly the same way as on the original carb.  That meant that the plate had to mimic the geometry of the original throttle quite closely.  It was easier than it sounds (and an old-timey HydraMatic man said I would never get it to work right).  The worst thing about the system is that modern engines are made to idle at higher speeds than our old carb engines and the EFI didn't like trying to idle as low as 450 (let alone 375rpm!).  The slightly higher idle speed made it harsher to go into and out of gear (from N to Dr or from N to R or R to Dr).  So if you are intent on installing EFI, ask about how low the idle can be set.

Having said all of that, I probably would install EFI on a 52-56 engine with dual exhaust and a 4bbl manifold, but not on a 49-51 engine.  The 49-51 engines perform extremely well with the Carter 2bbl carb.  Really, once you rebuild/restore that carb carefully, they are just fantastic performers -- lively, peppy, and not prone to much vapor lock. On the other hand, for the 52-56 engines, the vapor lock issues alone are enough to drive me to use EFI.  I am looking at an EFI system right now for a 55.

Here are some pictures of the EFI on the 49...