Depends on what you plan on doing with it, for moderate wheeling an auto will do fine, I beat the snot out of mine. If you plan on a Hammers type vehicle the auto will fall behind mostly due to the fact you will run out of horsepower due to larger tires and such. I keep mine at 31's though I've considered going to 33's. I have run up to 35's in another 4Runner I had and it did OK but power issues came into play at times. It had 4.88 axles gears which helped a lot. Currently your truck will have 4.37 gears and not 410's which would come in a 5 speed.
