727 ?

[Small Block]

I've heard the terms 727A and 727B when referring to trannys. Is there a difference and if so what.
Small Block

 

[74sundance]

727A fits small blocks and the 727-B fits the big blocks, 727-RG bolts to the six-cylinder blocks. The 904 comes in a 904-A, 904-RG, as well for some of the earlier 4-cylinders. Some higher performance 904 units were designated as 998s and 999s in the later 1970s.

 

[Small Block]

Thanks Sundance. As usuall there is someone on FBBO or FABO that has the answer. Thanks
Small Block