The transmission identification number can be found at the location described below:
Muncie 3 speed: On the boss above the filler plug.
Muncie 4 speed: On the right side of the transmission case at the right side of the lower rear of the cover flange.
Saginaw 3 and 4 speed (83 mm): On the lower right side of the case adjacent to the rear cover.
76 mm 3 and 4 speed: On the right side below the side cover.
Powerglide, Torque Drive, Turbo Hydra-Matic 350 to 1972 and Turbo Hydra-Matic 400: On the left upper flange of the transmission housing converter opening.
Turbo Hydra-Matic 200: Tag on right side of the transmission extension.
Turbo Hydra-Matic 250, 350 (1973 and later): On the right vertical surface of the oil pan.