88 4runner, automatic. What would be the best engine to replace my 22RE? I want to swap to a 6 cylinder.

4.3 chevy would probably be the easiest, and have the most readily available parts. THere are lots of people that do Toyota V6 motor swaps as well, but those are more involved due to fuel injection and such.

Keep in mind that you're going to be looking at a tranny swap also. That Toyota tranny is not the strongest. Most likely will fail if you put a powerful V6 in front of it.