Thread: Engine choice for a -57 Caddillac

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Hi guys,

happy new year and best wishes from Norway!

The classic american car scene is booming over here and I am right on it. I just sold off my stock -67 Skylark, and I am looking to start a mild custom project. The car in mind is a -57 Cadillac that I have at hand, and the plans are app. the following:

- brand new drivetrain
- lowered with air ride
- shaved body
- nice rims and a nice paint job

Nothing too fancy but I guess I have to start somewhere (even with these modest plans I could be in over my head...). My experience with american cars are limited to the Skylark, which I mainly just kept in good stock condition.

Now to the point. Before I actually buy the Caddy I would like to have some sort of plan in place regarding the drivetrain, to make sure it will all fall within my budget.

The primary conserns are:

- gas mileage (gas is $6/gallon over here)
- high streetability/cruiseability
- nice idle
- low maintenance (dayli driver during the summer season)
- some perfomance. This is hard to quantify, but hopefully 0-60 in like 5-7 seconds?

Now, my engine and tranny budget is $10k. I am looking for a crate engine, as turnkey as possible. I have been surfing the web for SBC, BBC, LSand even crate caddy engines. To be honest i have no idea what I really need.
Any suggestions?

Thanks in advance

Welcome. I did a restoration on one of these some years ago for a customer, pretty neat old cars.

The original 365 engines were not really too bad for their day, not a real ball of fire but a pretty decent cruiser. As an alternative to an engine swap, you could try to find either a one of the dual quad or Tri-power setups that were available for them (kind of rare but I have occasionally seeen both on E Bay every once in a while). Send the valve covers and a few odds and ends off to be chromed and yhou have a nice resto rod.

If you have your heart set on an engine swap, IMO a 472/500 CI Caddy motor with a TH-400 would be the way to go. I'd leave everything pretty much stock on the engine but some of the Caddy sites can give you a preyy good idea on what mods will work well for what you want.

One of the keys to getting pretty decent gas milage with the big inch Caddys is to take advantage of the massive amount of torque with set of high rear end gears. The problem is as far as I know you aren't going to find many choices for your stocfk rear end, leaving you with only a couple of choices, either a rear end swap to a unit that more gear choices are available or an overdrive transmission.

While the transmission route does have a certain appeal (such as a 700R4) keep in mind it will have to be very well built to handle 500 foot pounds of torque in a very heavy car.

I'm sure others will have different opinions, but that;s mine, hope it helps.

That's a big heavy boat, its gonna need some torque. My preference would be a 500 Cad, or a good rebuild of the original engine. A BBC would power it, I doubt you would be happy with a SBC. You aren't going to get much gas mileage no matter what engine you use, that thing's heavier than a one-ton truck!

Mike P and R Pope are right on the money. Put a Caddy back in it, either the stock year or a 472-500.

Bulletproof, powerful, and they fill up the engine bay. I personally hate to look into someones big Caddy , Olds, or Buick and see a tiny 350 Chev in there. Looks lost. I realize it is sensible, but......

Gas milage isn't going to be great regardless of what you install.....theres alot of iron to move there.

Good luck.

I would agree with a Caddy engine, the bigger, the better.

500 sounds impressive, and will give plenty of torque to move it around easily.

This should enhance the value of the car more than something from another manufacturer.

Go-faster goodies for the 472/500...
http://cad500parts.com/
http://www.500cid.com/

I'll add my vote for the 472/500 CADDY and T400.

a pontaic 400 with 675HP at the wheels whit auto tranny and a 1/4 speeeeeed of 9 will cost you 11K at almost any shop and well as far as fuel milage well with a caddy i dont think you're going to get above what a PETERBILT gets

Here's another vote for a Caddy engine, either a 472 or a 500. As for the trans, a Turbo 400 is great, but you might also want to see if a newer 4L80 or 4L65E will work behind/bolt-up to that engine. It would have the ability to handle the power and give an overdrive to slightly increase mileage.

Originally posted by sweet60n70chuvy
a pontaic 400 with 675HP at the wheels whit auto tranny and a 1/4 speeeeeed of 9 will cost you 11K at almost any shop and well as far as fuel milage well with a caddy i dont think you're going to get above what a PETERBILT gets

The Caddie will cost way less than 11k., more like 5-6000 if your building it up good. Pontiac engines have a weird designe for the way the headders/ manifolds come off the heads ( a sharp angle ) that makes it harder to make power because it's breathing disability. They may not get great MPG, but then again no big block does, and a pontiac 400 could tecnicly be considered a big block ( 389-400 used same basic block designe ), so theres not much diffrence