50, I plan on installing the 6.2 and 4sp OD trannie from my old 84 van into the 41 truck. But I am going to use a newer 3/4 ton Chevy frame. This combo in the van averaged 23.5 MPG. In the truck with a heavier frame, gears and all it won't be that good. But still a lot better than the 292 I could use. You should have plenty of power with the Cummins. Mike
