gtv6 engine swaps

A later Alfa V6, either 3liter 2valve from a 164 or Milano/75, or the just superceded 24valve motor would be the most sensible swap.

Adapting any non-alfa engine will be something of a challenge due to the Alfettas unconventional rear mounted transmission.

Also the fact that you are a 'newbie' and are asking such a question suggests that you would be much much better off sticking with a factory drivetrain.

I have an engine from an '84 GTV6 for sale, with 55k miles on it, runs great. idk how much its worth, not much seeming as everyone has 2 or 3 laying around.