67 valiant slant trans to 77 truck slant trans

Yes the motor out of the truck will bolt to your 67 transmission. Get with Charrlie_S to buy a bushing to use Your 67 transmission and small snout converter with the later crank. Or, use the complete 77 engine and transmission as a unit. Being from a 3/4 ton truck, it probably has a 727 which will fit into the 67 body.

EDIT: I would probably use the 77 engine transmission as long as both are in good shape.

EDIT #2 - if the 77 transmission is for a 4WD, then no can't use in the 67