1. custom engine mounts, crossmember, gearbox mount, tailshaft, upgraded diff, suspension, brakes, wiring IE Everything on a commodore.
2. yes. alot of difference. Not in the way they go in, internally.
3. I wouldnt undertake this sort of project unless I could do most work myself. (welding, etc) Why? because its simply not economical to pay someone to do the work. That and its not rocket science.