The later Max's came with same engine as the 1st gen V6 Montero. The V6 would be an easier swap in my opinion because all the parts are plug and play from research, no need to fabricate a intake manifold or coolant pipes. The motor mounts would come from a 99-03 Montero Sport. For the DOHC 6G72 all the coolant tubes and intake manifold can be used from a Kia Sorento because it uses the same DOHC 6G motor found in the Montero RS and is easier to find.