67 was the change in the crank flange and torque converter hub (and also input spline count) so you'll need an adapter ring to run anything 68 and up with the 67 trans. any 273 from 67 to 64 won't have any compatibility issues.
Yep....the adapter ring goes in the tail of the crank where the flexplate bolts on. It keeps the nose of the converter from wobbling around in the back of the crank. Cheap fix to make the 88 motor and 67 trans work together.