Dennis, I have a MTDI Caddy in progress. I planning to use a 9A with a .71 fifth,195-205 50 15 tires, .205 nozzles and intercooler. Big drop between 4th and 5th but I think the TDI in a 1600lb Caddy can handle it. Thought about swapping a 3.67 ring gear into the FF trans with bolt kit, but I think the close ratio will be more fun.