Just pulled the factory numbers matching 4spd out of my 70 Stage 1 to put on shelf and install a Tremac 5 spd and new clutch etc Stupid question... Is it a Borg Warner or a Muncie?
Borg Warner T-10 has a 9 bolt side cover (w/ rounded bottom), Muncie has a 7 bolt cover. Gorgeous car, BTW.
Guessing that is a Muncie M-20/21. The Borg Warner was used in the '75 to '81 time frame. No idea why the changeover occurred after the '74 model year.