[Brad54]

You'd be better off going with a later front cross member and dropping it onto the '62 chassis, and then find the rear end you want and put it in. You'll need to have the saddles moved on the rear, but that's easier than moving cab mounts.

You'd also need to move the bed mounting points as well--the stringers/mounts for the bed have different holes.

The bumpers will also need to be changed, because they are different too.

Clutch linkage and brake master cylinder conversion is easier on a '63-up, but that's all on the body and not the frame.

-Brad