How do you tell the difference between

[Robbie]

How can I tell the difference between a 1970 Cadillac 472 engine and a 1970 Cadillac Eldorado 500 engine? When I looked at the engine I thought it was a 472 but was told it was 1970 eldo 500.

This engine was put into a 50s cadillac that is being parted out now. It's rear wheel drive so it must have a Turbo 400. Can a Eldorado trans bolt up to any 472 or 500?  Are the transmissions interchangable with the engines?

Thanks,

Robert
cadfan1959@aol.com

[Stampie]

The only real 100% for sure way is to measure the stroke.  A wooden dowel down the sparkplug hole will do it.  The 500 stroke is 4.304 inch vs. 4.060 for the 472.  Beware anyone claiming a 70 500 engine.  Just about every 472, 500, 425 and even some 368's get claimed as a 70 500 at some point.

Stampie

[TJ Hopland]

What stampie said is correct.     70-74 only eldo's came with 500's.  75-76 everything but Seville came with 500's.
Everyone wants to have a 70 because from the factory that was the highest HP.   Unless you are going for some crazy all out abuse and performance any of the engines will do fine.   472/500 is not even that much different in real world butt dyno power.  Big thing you want to look at or take into consideration is the heads.  68-70 motors were high compression 71-76 low.  71-73 they kept the same heads and dished the pistons to lower compression. 74 they modified the heads to get low compression with fairly normal dished (or flatop in the 74 472) pistons.   Pistons can be had for the early heads either high or low.  Later heads give you low comp.  Cams and general tuning and restrictions were the reason for the steady loss of power over the years.  If you wanted to a 76 500 could easily be built to put out more power than the factory 70.  The 70 had some special parts that could be a benefit for a really high end high power build.  If it is a 70 you could likely trade the 70 bits off to get good usable stuff for your project.

The only difference between the FWD eldo motor and the RWD ones is the oil pan, oil pickup tube, dipstick, starter, and drivers side exhaust manifold.   The eldo oil pan is more like a chevy pan with a rear sump so it is sought after for most swaps and they are getting hard to find, typical used ones start around $200.  The RWD cars used a front sump that does not tend to fit much other than cadillacs from that era.   The 77- 425/368 used a mid sump that works in many swaps.

Check out stampies modified site (link at the bottom of his post) for more info and links about the 500's and swaps.