This will be my first traditional hot rod build, so please be patient with me. I'd like to do a Cadillac engine with an automatic. Tell me why this might be a terrible idea vs. a SB Chevy with an automatic instead. Also, is any of the three Cadillacs significantly less expensive/easier overall compared to the others?
Sounds good to me. Did one of those years have a bad trans when compared to the others? Charlie Stephens
The biggest issue will be finding someone capable of building the transmission. Not too many old timers left that are interested in that sort of thing. These guys have adaptors for the Cad engines to fit Chevy automatic and manual transmissions. I had one of their kits behind my '59 390 with a 5 speed, worked wonderfully. Check em out. Transmission Adapters Proudly Made in USA - Speed Gems -Abone.
Just as flamedabone said. I have a friend who has a '51 Merc custom with a '55 Cad 331 with a 350 Chevy turbo transmission. Works great, lots of them around, and not that expensive. I would not buy a 49-54 engine. I would go with a 55-60. Stay away from Cadillac hydra-matic transmissions. They are heavy and finding a re-builder may be difficult. When searching for any engine as old as these, you are basically buying a core, so keep that in mind price wise. A fresh re-build with reciepts is a different story. As for prices of 331's, 365's, or 390's, I wouldn't say any are cheap. Depends on how long you are willing to search. I searched for about 10 months for my 55 331 and finally found one on craigslist 60 miles from where I live. After a little back and forth I paid $750 for it and I had to pull it from the car. The engine was totally complete, carb to oilpan, starter etc. Pulled the valve covers and was surprised how clean the rocker arms and valve springs were. Haven't re-built it yet so don't know what it's going to cost. 390's are 10 1/4- 10 1/2 compression so keep that in mind. If you haven't done so, check out root hawgs Cadillac engines thread.
Turbo 400 Hydramatic came out in late 64 I believe. If you go with an earlier engine you will be running an original Hydramatic which will require extra effort and dollars finding someone knowledgeable to work on it. I have one and it’s a steep learning curve. Transmission adapters are spendy. With that being said, a 331 Cadillac engine is a thing of beauty.
As compared to the typical belly-button engine and transmission the early Cadillac will require more money, thought and effort. Which isn't a bad thing... I have a 331 powered A roadster and a 390 powered '40 Ford so I've been through it. They are all good engines but some bearings and US made lifters for the 331 have become un-obtainium. 365's and 390's still seem to be OK for parts availability. My 331 has about 8.5-1 compression and runs well on regular gas, but the 390 was advertised at 10.25-1 and requires premium unless I want to retard the timing a lot. And the late 390's have full flow oil filtration which is a good thing in my book. As far a transmissions go, run what you want. However, though it's heavy the early Hydro's are a good, tough transmission and despite what others say they are not hard to work on and parts are still available from Fatsco and NW Transmission.
In my 49 Buick I have a 1970 Cad 472. Not traditional, but 375 HP and close to 500 ft lbs of torque bone stock at about 3200 rpm. High nickel block, mine had 100,000 miles on it, and when I pulled the heads you could still see cross hatching in the cylinders. New gaskets, valve seals, and timing chain and sprocket and good to go.
An oldie but a goody! https://www.jalopyjournal.com/forum/threads/tech-info-cadillac-ohv-v8s-1949-1962.8282/
I just heard about a 390 that I want to put in my Studebaker Lark wagon. I saw a mention that made me worry. Are there two different 390s or are they the same as far as interchangeability goes? Warren
Cadillac redesigned their engines in 1963 and while the 390 for 63 had the same displacement that is the only thing that is the same. If the distributor is in the front then it is the 63 version. What you want is the 62 and older engines
331/365/390 Cads are all good mills. Trans adapters for GM autos are reasonably priced. In short... do it.
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