Hey everybody, I'd like your thoughts on the following scenario. I have a 32 3 window I was going to put a Cadillac engine in. It currently is running a 65 289 that came with the car. I originally purchased a 1959 390 engine. It turns freely but I never heard it run so I had plans to have it rebuilt. I also have access to my wife's 1950 Cadillac that has a running 331 (but should probably be rebuilt) we were going to eventually pull and display in the garage . It would be awhile till I was able to use the 331. The 390 is out of the car but I'm also fixin to move to another state and don't know if I really want to transport it. I like the cool factor of the 331 but it's a real poochy bastard. The 390 would get me more horsepower but as previously stated the condition is unknown and I'm moving. As far as the 32 I was going to eventually restore it to be a drylakes racer homage but one that wasn't going to be a strict "only parts prior to 1950s allowed" type build. So what say you? 390 or 331 and why? Appreciate any and all opinions! Edit: Sounds like the 390 is the way to go. Thanks everybody!
Do a compression test on the 390. If it does decent give her a try and sell the 289. Why were you going to rip apart the 50 caddy?
Appearance-wise, either the 331 or the 390 will have the same effect. Being in same series of the Cadillac engine family they both have the cool old engine factor. Good idea to check the compression and try to evaluate the condition of the 390. That would be preferred if it is good shape, even if you do a quick rering, bearings, and freshen up the heads rebuild. Moving is never fun, and we all seem to have too many old cars, car parts and tools when it comes time to move it all. Keep the 32 coupe with the 289 and running until you move. Take the 390 in the move, and deal with the drivetrain swap once settled in the new place.
390. Here's some light reading for ya. https://www.jalopyjournal.com/forum/threads/lets-talk-cadillac-331s-365-and-390s.1015067/
First and foremost, what transmission do you plan to use? The 331" has the extended bell housing on the back of the block. The 390" is the flat black with the B-O-P bolt pattern. Bottom line, the 390" is preferrable for displacement, parts, tranny fit and doesn't cost any more to build. jack vines
If you have a flywheel & starter for the 390, throw a carb on it & fire it up where it sits. Like someone said, maybe just a freshen up is all it needs. A 390 is so much better than a 331. (My opinion because that's what I run)
I have a '62 390 in my '40 Ford and a '55 331 in my A roadster. I'd go with the 390 mainly because some rebuild parts are getting hard to find for the 331. Some main bearing sizes are now unobtanium unless you get lucky and find someone that happens to have a set on the shelf. At this time 390 bearings, rings and lifters are much easier to find. The only advantage I can see to using the early 331 is that the flat plate transmission adapters are pretty easy to find. It took quite a while for me to find the 390 to early Ford adapter I needed for my '40.
I know the 390 in the 62 coupe DeVille I had in 01 was a nice running little engine. Had a rumble from the lakes pipes but sure was a smooth running lil engine
It's basically the same engine, might as well have more cubes. Might be a little harder to find a bellhousing adapter but they're out there.
They make adapters. Check with Wilcap and Speed Gems. Check out this thread. https://www.jalopyjournal.com/forum/threads/cadillac-331-390-adapter-kits.1309922/
I built a 390 for my '34 recently. The little motor makes a giant pile of torque, looks cool and runs great. The down side is those motors have stupid oiling systems and parts are expensive. Here is the adaptor from Speed Gems. Not cheap, but drama free. I run a TKX behind it and the little car runs 85 at 2200 rpms and never breaks a sweat. The 390 makes an ass load more power than either of the other two engines. -Abone.
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