I've searched a around a bit but haven't dug into my service manuals yet, just hoping for a couple of quick "should or shouldn't work" type answers. I'll work out the details later. I have a 97 short bed with a 4.3. I might be able to get a 5.7 motor, trans and harness w/pcm from a 98 for a decent price. Would it make more sense to try to use the 98 harness, or just change what I need on the 97 4.3 harness to make it work with the 98 pcm and 5.7? Or would it make more sense to try and find a 97 5.7 harness and computer? Motor mounts: Are new motor mounts complete, or is there a separate piece on the front cross member that I have to find? And thinking forward for a supercharger are there larger cc combustion chamber 5.7 vortec heads that I could bolt on while I'm at it or is the smaller cc chamber a defining element of the vortec heads?