There is a rare bell housing used on early versions of the RPO MY6. That has both the Chev and Dodge (A833 trans) bolt patterns. I don't know that the A833 bolt pattern and NV4500 are the same. The MY6 was used from 82-86, so the bell housing I'm guessing would be about an 82.

Larry

I don't own a vehicle that isn't old enough to drink.