Technical Flathead interchangeability

Have a 1932 Ford that is currently running an 8ba motor. It has a trans adaptor that makes a gm manual trans work with the 8ba.
The 8ba motor needs replacing /rebuilding . But I do have a rebuilt 21 stud motor . My question is how many things would I need to change in order to make the 21 stud motor work in place of where the existing 8ba was ? Would motor mounts have to be relocated /changed ?Different trans adapter ? I will likely have another 8ba built but shop won’t be able to get that done for 4-6 months cuz they are really busy . So I figured maybe the 21 stud could get me back on the road till the other motor is done and ready

 

What year block is your 21 stud?
35-36 and 37 engines have a different front mount configuration.
You most likely would not be happy with the smaller engine. There is a considerable difference in power. 8ba’s run much smoother.
Id suggest selling the small rebuilt 21 stud engine and finding a good used 8ba in the mean time since you intend to just change it out after your 8ba is rebuilt.

 

Looks interesting.

https://www.jalopyjournal.com/forum/threads/flathead-239-8ba.1276740/

https://www.jalopyjournal.com/forum/threads/8ba-flathead-block-4in-crank.1270706/

https://www.jalopyjournal.com/forum/threads/52-merc-flathead.1265800/

 

I’ve only had a few FH V8’s, but never an 8ba. I’d ***ume (surely don’t know) the FH trans would be the same circular bolt pattern for an 8ba and say a 59a with the integral bell housing casted with the block. Definitely mock it up first. The 221 (I put one on a ‘42 Ford PU) moved the truck just fine, but was all flatland driving and local highways/town driving.

 

Your clutch is going to be more problems than it’s worth. The late flywheel probably has a larger clutch on it to fit the GM trans. That won’t work on the early 21 flywheel. And you can’t put the late flywheel on the early engine.

I’d do as suggested and look for a used 8BA to drop in temporarily.

 

Pretend it's '55 and drop in a 265.

 

FoMoCo…interchangeability…what is that, said FoMoCo head engineer!

 

Thanks guys , my gut feeling was there would be a few things that wouldn’t be the same . I will search out another 8ba to keep the swap as simple as possible

 

Check out the ford barn.com every question you have can be answered there.