New Slant 6 put in the 64

1. A 77 slant six should have had a solid lifter cam with adjustable rockers from the factory. 81 was the first year for full production of the hydraulic cam (a few built 78-80 for testing).

2. A 64 torque converter's snout is too small to snugly fit into the back of a 77 crank. I.e., the early trans will bolt to the later motor, but the crank won't hold the early torque converter centered. You need an adapter ring to fit over the torque converter snout to precisely locate the converter in the crank. The torque converter bolts alone won't do it.