Engine swap for 91 4WD

I have a 91 4wd V6 4 runner with 161k miles. The engine is feeling very weak, (0-60 in 35 sec) and it might be due for a rebuild/replace. I dont want to swap a 16 year old motor for another 16 year old motor, and I would not mind getting a little extra power since I am planning on lifting it an putting 33s under it. would a newer model Toyota V6 be a good swap? I am not worried about mpgs because it CANNOT get any worse than it is now, and it will be my mud toy not a daily driver. Any ideas would be great. Oh and one more thing, how much wheel offset would I need to run 12.5 in wide tires?

The conversion to a 5VZ-FE (3.4 L) is fairly common. Here are a couple of links to kits

http://www.offroadsolutions.com/technicalarticles/34l_conversion_kit_auto.htm
http://www.offroadsolutions.com/technicalarticles/34l_conversion_kit.htm

Wow I was not planning on spending 12 grand on a motor swap, I could completly rebuild the old block, install a TRD supercharger, and do my lift for half that much. Are there any ways to get a few more ponies out of the SOHC engine. I prob could do a rebuild for a grand, and port the heads, but would that be worth it?