There are a LOT of interchangeable things, but I dont think a diesel tranny onto a gas engine is a good idea - IF you could get it to work. I bet Charles or Chuck would know the answer!

There are too many interchangeable things to list in here. Not all are identical, but some will yield improvements on some vehicles while on others, they'll be bad moves. For example, one I did myself, 3.5 heads on a 4.5 engine will increase your compression - conversely, 4.5 heads on a 3.5 engine will let you run on 87, but you wouldn't even think about it. Lots of people don't want to do the welding, but almost any modern V8 Benz engine will fit into a 108 or 109 chassis I believe.