I have always had Automatic transmissions so when a friend asked a question I told him I would post it on moparts for him.

Here is the question.

Are A-Body 3 speed and 4 speed Bellhousings interchangeable?

Which is more rare on an A_body a 3 or a 4 speed?

Thanks Guys

Same bell housing for either. What's more rare depends on what year & model car you have, it's about 50% each on average, 3 speed was the base trans most years so quite a few were made, 4 speed was an extra cost option and most prefer them.

I wouldnt say they are completely interchangable. It would depend on the diameter of the input bearing retainer

To clearify, 1970-71 (and possibly later) was what I was talking about.

Just to throw a kink in the machine but /6's didn't have the dual bolt pattern bellhousings like the V-8's did until late. Around 76 or later when they started the OD 4 speeds.

He didn't say what engine.

He didn't say allot of things we'd need to know to really nail down his question

Slightly off topic, We used an A230 3 speed from a 70's A body(I believe) on our circle burner(9-1 2bbl 360) & nary a problem. Syncho in 1st also.

Where's the fun in that?

The friend that asked me has a 1972 Dodge Demon 340 with a 3 speed. He wanted to know if he could put a 4 speed trans in it and still use his same bell housing.

Thanks for the help guys.

Great, then my assumption paid off, the answer is yes (still) but he'll need to use a 4 speed with the correct front bearing retainer size as mentioned above by another poster.

NOt all bellhousings are dual drilled, both 3 and 4 speed patterns. General rule of thumb, iron bell = not dual drilled, aluminum = dual drilled.