[brennecke]

472 and 500 are same bore different stroke, so a 472 wouldn't be bad. Look at the intake on the motor. If it is a single plane intake, you're looking at a 425. If you aren't going to build that motor up, I think you could get away with the overdrive tranny, just be super careful in first gear. The guys at MTS told me with a 3.73 rear I'd be on the bleeding edge of drivability (rapped out at highway speed and not much chance of hooking up on street tires). They recommended mid 3's or lower.
I'll find out how to identify the 472 and let you know.