I run the 65 trans in my car. The rotating assy in the trans can be swapped from a late model except for the output shaft,case,and tail housing. I talked to the owner of Imperial (he's not far from me). The only concern he has is the releasing from park. He says his set-up could be damaged pulling the lever out of park on an incline. As far as shifting he had no issues. The push button valve body detent spring on the rooster combo is much weaker than a late model. I don't remeber if their set-up changes that or not. As far as the 65 set-up. I've run thousands of passes with no issues. The shift mechanism is very simple. Cables in good condition and proper adjustment is all that is required. I may see them at the Chrysler swap meet this weekend,they're usaully there. If you have any questions PM me before Sunday.
Doug