adapter plate 67 deville rochester convert to Holly

[TD Alex]

Bought a holly performer carb to replace rochester quad.  The adapter plate sent does not cover the intake manifold completely.   I called Summit and they sent another one with same issue.  Made a gasket to cover but not 100% confident.  Is there an off the shelf adapter plate from somewhere??

["Cadillac Kid" Greg Surfas 15364]

Get a 1967-1970 Quadrajet base gasket and cut out an 1/8"
Steel plate to conform with the outside lines and the inside openings of the gasket leaving the "slot" in the front where the '67 is open to the exhaust opening in the manifold solid. Still going to cook the carb because of the heat. They changed design of the carb in '71 to eliminate the heating issue.
Greg Surfas

[TD Alex]

Greg, when you say "steel plate'.  Are you meaning to have an adapter plate machined vs an "off the shelf"?  Also, "leaving the "slot" in the front where the '67 is open to the exhaust opening in the manifold solid."  Are you recommending covering the "slot" with gasket? Covering the exhaust slot with gasket material?  I'm not clear?  Appreciate your input, Trent

["Cadillac Kid" Greg Surfas 15364]

The Edelebrock "QJ" is a copy of the later   Chevy carb. What I was suggesting is that you take the early 67-71  base gasket a d use it for a template to make a steel " lock off"
Plate to cover the exhaust slot (intended for carb warm up) in the intake manifold. Then use the base gasket that is intended for your carb
Greg Surfas

[fishnjim]

Clarify: "Performer" is a Edelbrock model.   "Performance" is the Holley version.

These did not come with Holley, so adapting is more difficult, but should not be impossible unless the bolt pattern/base is completely different.
The Edelbrock should bolt right up as they were the Carter of the day and interchangeable with Rochester.
I'd look at the holley site and see what they show available.   Sometimes Summit doesn't carry everything.

[TJ Hopland]

67 Cads came with a Quadrajet so only something designed specifically to replace a Quadrajet will bolt directly.   In the aftermarket the Quadrajet mounting is often called spread bore.  You end up needing an adapter like the one below which also takes care of the different mounting hole locations.   I would think you would also want/need to use the original metal 'shim' base gaskets to deal with the exhaust port,  basically treat that adapter like the stock carb and use the stock stuff between the intake and adapter. 



This one from Jegs just happened to be the first one to pop up in a quick search but I believe all the usual brands and sellers have something similar.   There are also versions that are open in the center but for these earlier cars with that exhaust port I think you need the 4 hole so you have that solid area in the center.
https://www.jegs.com/i/Edelbrock/350/2696/10002/-1?gclid=EAIaIQobChMI4YjP3aau8gIVN3xvBB2D2gueEAQYAiABEgKs_PD_BwE

Even with this style of adapter you need to carefully check the fit with everything because the Quadrajets didn't have much surface area around those huge secondary openings so it doesn't take much of a mismatch or alignment issue to not seal up well.

[TD Alex]

Good Stuff!!  Wish I had had this before I struggled to get the Holley on.  I am reading all the comments and going to figure out which way to go from where I am.

For what it's worth: I tried calling Eldebrock customer support multiple times over a week. I was going for the Elde on a recommendation.  After all the calls and waiting for up to an hour at a time on hold during the week.  I gave up and just called Summit to see what they suggested.  When I spoke with the rep at Summit he lead me to believe that Elde might not fit.  Also, that Elde carb was on back order and lead me to the Holley.

Thank you all for taking the time to write.  Best Regards TD

["Cadillac Kid" Greg Surfas 15364]

For a stock 429 motor there is NOTHING that can beat a correctly built and adjusted Quadrajet.  Bar none
Greg Surfas

[TJ Hopland]

To add to what Greg said its also a bonus that if you stick with the QJ you don't have to screw around trying to make the kickdown switch work and I assume this also has a switch pitch?   Most of the other GM's used a pedal mounted switch so there are not that many options for the kickdown and I assume even less for the switch pitch.   

[TD Alex]

I really did want the original Rochester carb and get it rebuilt.  The car now has 70k orginal miles and is very good to excellent original condition.  It has had minimal work done to it other than typical wear item maintenance.  I really want to keep the original integrity of the car.  With that said; I spent a lot of time and searching regarding getting the rochester rebuilt.  Locally and across the USA.  I had a couple long convos with a guy at a part house that only does rochester carb parts in Missouri. At one point I did consider giving it a go and doing it myself.   I was cautioned by the guy in MO, whom I thought was a reputable and knowledgeable, that particular carb was not one for a first time rebuilder.  So more time searching. I called every place I could find on the internet to exchange mine for a rebuild.  With no luck.  Only place I found was in texas to rebuild mine and was given a four month lead time.   

So, here I am with what I though would be a good fix.  However the carb change does not seem to perform a 100%.  BTW I am in NE Wisconsin with this car and have not found too many mechanics that are even interested on working on a classic car.  I have some mechanical aptitude and desire to work on car.  Which I have done few simple maintenance items.  However, I really have limited tools and no equipment per se to do much work myself. So, any additional ideas on getting my original carb rebuilt would be appreciated. 

[Daryl Chesterman]

I would recommend this company for a carburetor rebuild.  When they get done with it, it will look and operate like factory new!!!  You can call them and talk to them about price and what you get for a rebuild.  They are not cheap, but the results will speak for itself.  They did a Carter AFB and an Autolite 2100 for me and I was extremely pleased with the results.

     https://daytonaparts.com/

Daryl Chesterman

[71 Fleetwood]

I did consider giving it a go and doing it myself.   I was cautioned by the guy in MO, whom I thought was a reputable and knowledgeable, that particular carb was not one for a first time rebuilder.


So as not to hijack the conversation, I'll start a new thread "First Time Rochester Rebuild"

[35-709]

I would recommend this company for a carburetor rebuild.  When they get done with it, it will look and operate like factory new!!!  You can call them and talk to them about price and what you get for a rebuild.  They are not cheap, but the results will speak for itself.  They did a Carter AFB and an Autolite 2100 for me and I was extremely pleased with the results.

     https://daytonaparts.com/

Daryl Chesterman

TD,
     We have talked about your problem, and daytonaparts.com, through this forum's PM system before.  By the time you get done trying to make an aftermarket piece work, not intended for your car, you will have spent more time, and money, and experience more frustration trying to make it work right than if you had talked to daytonaparts and sent them your carb in the first place.  You would then have a carb that was designed for your car, fits right, and works right and would no doubt outlast your ownership of the car.  I personally do not believe you will ever be happy with that Holley unless maybe you can get someone like Greg Surfas to come to your house and install it and set it up for you.  My opinion, and I wish you the best of luck with it.
Geoff N.
   

[TJ Hopland]

I have had good service from these guys who are just north of Minneapolis.  Not the closest to NE WI but maybe closer than some other options.   No idea what their lead time is these days,  last one I did was less than a week but it was a while ago.

https://www.thecarburetorshopus.com/

[wheikkila]

After reading this. I recommend you send your carb away to be rebuilt. You said you have limited skills and tools to swap the carb. Well that is only half the problem. Once you swap the carb and maybe figure out how to make everything work. You still have to tune the carb to the engine. That is one thing most mechanics of today don't know how to do. All they have worked on is FI. I'm not trying to discourage you. It's just hard to make a good decision if you don't have all the facts. I have a 74 super beetle with an 1850 cc engine with duel carbs. I just sent them out to be rebuilt. I could buy new ones. But I would have to set them up myself. By having them rebuilt. I give them all the specs of my engine and they set them up. When I get them I just have to install them. Yes, it is going to take 60 to 90 days before I get them back. But that is part of owning our cars. I wish you the best on this.
Thanks Wayne           

[TD Alex]

Thanks y' all for the all the input.  Old blue is running with the Holley.  However, I don't like the jerry rig set-up.  I am going to keep with my intention in keeping the original integrity of car.   Sending the QJ out for rebuild would be the easiest to do.  However, I am a bit of a masochist (I play a lot of golf) and like a challenge.  Therefore, I am going to go for the rebuild myself.  Like my Uncle Otto always said:  "Ain't no help like your own help."  Cruise on, TD