Hy JBTrue, let me start by saying that I have never done this swap, like you I have read a lot of descriptions, and seen a few completed swaps. Are you asking if you can keep the crossmember that supported the rear of the engine? I'm not sure if that crossmember would have to be removed or not, but I do know that you could not install the engine and transmission in one piece with that crossmember in place. I have never seen this swap accomplished without moving the steering box outboard of the frame somewhat, there are no manifolds/headers that I'm aware of that will clear the steering box in its stock location. As far as I have seen the radiator/fan should be fine, and no notching of the cab is required, hope that helps.
