TREMEC RAB/RAN/RAT 1965-78 Cars, 1965-87 Trucks
Cast iron, side loaded case with a 9-bolt cover on top and side shifter linkage. Main shaft reverse gear is located on the outside of the 1st gear synchro sleeve. The cluster gear is a 3-step helical cut gear.
Its one of these three. Most likely the Rat with the six cylinder. engine.