different 727 transmissions
The part # will identify which application,. basically the 383 had six pinions, lighter clutches, etc. The 383 four barrel and 440 single exhaust had seven pinions, and more heavy duty parts inside. The Roadrunner/Superbee 68-69 and 67-69 440 HP had eight pinions, more heavy duty parts. The Hemis had eight, but I believe a different barrel as well, more clutches, bronze bushing,etc. I believe the 69-70 440 six barrel also had a variation all to it's own as well. The details are in the factory parts book, as I have exhausted my knowledge of the group. Things changed in 70', so to be sure a person has the HP trans, they need to look at the part number. I found a 70' VIN# correct 383 four barrel trans behind a 440 hp one time, and a 23 spline four speed behind a 71' 440HP engine. so Chrysler was quietly trying to save money, I guess. We all know what path this led to, sadly.