1) A friend should not let "My friend" consider an impractical swap.

2) As noted above, emission inspections will dictate a great deal.

3) What is the mechanical competence level of the "friend"?

4) The least labor swap will be to install an M116-4.2. The 4.2 is a direct bolt-in (including the trans). The camshafts can be re-keyed to a more advanced position. The Gen I fuel and ignition systems will be retained.