Anyone done an LS Swap on a 50s Caddy?

[chelonian]

The old 365 is tired and I would like a little more torque to move the behemoth 57 Seville. I saw a couple LS engines in some old caddies at the Daytona Turkey Rod Run but could never talk to the owners. ANy major pitfalls with this? I didnt see any cutting anywhere, just some motor mount adaptors. Like a dumbass I forgot to look at the trannies, but its obviously all do-able.

[dn010]

You'll have better luck checking in here:

https://www.modifiedcadillac.org/forum/

[Abe Lugo]

TBH the modified forum is really slow.  You might want to try a streetrodders.Com forum or the cadillac forums.

  Even the search helps.

I would say wait for the owners next time and get their info. 
See what worked or didn't work for them.   

1950's cadillac ls swap forum in google

https://www.google.com/search?q=1950%27s+cadillac+ls+swap+forum&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari

["Cadillac Kid" Greg Surfas 15364]

Last LS swap Tran about $30K. You can do a lot of rebuilding your motor for that
Greg Surfas

[fishnjim]

https://www.streetmusclemag.com/features/meet-rosie-the-restomod-1957-cadillac-seville/

[jwwseville60]

Remember that a new LS3 is 430 bhp.
Disc brakes and stiffer springs are needed for safety.
Your 1957 365 makes about 185 bhp SAE net with a fresh rebuild.
Its a huge difference.

Cadillacs are heavy with a stout frame, but the suspension components will take a bigger strain. Keep in mind the metal fatigue of 65 years as well.

Gross BHP x 30% gives you what to deduct. (Estimation)

A nice alternative is the GM 5.3 LS, which makes a good 350 bhp. (New)

[TJ Hopland]

One thing in the LS favor is since its a current production engine you got a decent chance of getting quality parts for one.  Can't really say that about most out of production engines anymore.  Both my recent personal experience and what I see and read garbage parts even from good brands is a huge problem.   

[jwwseville60]

The 57 street rod posted above by fishnjim is a very nice car.

However, like most "engine-is-the star" hotrod articles, they dont show what has been done underneath. Rodders with "follow the lemmings over the cliff" black t-shirts and backwards black caps always seem to do the same things, no offense. "Lets slam it on air springs!"
Thats getting old. So are 24 in. rims on classic Caddies, their frames dragging pavement along.

Hopefully, with 650 bhp, they went to a custom-made frame.
But there's an issue...

The stock-looking 15 inch wheels on "Rosie" cannot house proper size brakes to efficiently stop a 5000 lb car with 650 bhp. Discs fade much less, but dont stop better than drums. If they had gone with 18 in. billet turbine Caddy wheels it would have had the room for bigger HP brakes. But bigger wheels and stickier tires put vastly more pressure on suspension components. A person must sweat all the details. Few do, sadly.

I raced professionally for 18 years. We had excellent big brakes, a super-strong chassis and a lightweight car (Corvette GT1).
That 57 "Rosie" rod is the opposite.
All show, all go...but no STOP.

We live in a golden age of super-high BHP modern engines, and 1000 bhp restomods are legion.
I respectfully urge anyone on this forum who considers an LS swap to please mind the finer details. That said, I too was once considering an LS swap, but reconsidered. Its a good GM Caddy choice, an excellent engine, don't get me wrong... but remember the devil's details:

• Huge acceleration squat at the rear.
• A lighter engine up front by 250 lbs or more. (weight bias issues)
• Suspension strain
• Cooling issues
• sway bar needed?
• More electronics
• High RPM engine
• Louder engine in a car that is not sound proofed like modern ones
• Bigger brakes needed
• HD springs and shocks
• Etc, etc, yackedy-yack,,,,


How to make a stunning, Harley Earl-designed 1957 Seville look like a bargain basement, cookie-cutter 1980s-style Chevy hotrod in ubiquitous Kandy apple red:
https://buy.motorious.com/articles/news/344693/this-1957-cadillac-eldorado-restomod-is-a-showstopper/

[jwwseville60]

OK, thanks for letting me rant!
On second thought, I wouldn't mind putting an LS3   in my 61 CDV like this car: