Technical 364 401 425 Buick Nailhead ????

Question, are the bellhousing bolt patterns, starter location and end of crank the same for the 364 401 425? Thanks!

 

Bell patterns and starter location I believe are the same. However in 1964, the 401 and 425 crank ends are set up for ST400 automatic, which is different than the previous year's Dynaflow crank.

 

It is fairly easy to put the ST400 behind a pre-64 401 or 425. Just get a flexplate from the 64 to 66 engines. Open up the crank pilot hole to fit on the pre-64 engine. Then put a starter off a 64 to 66 engine in the pre-64 engine.

But you won't be able to do this to the 364 since the balance is different.

The bell pattern changes when you go to the 264/322.