I had a stock 86 4Runner and just put a 2 1/4" exhaust on it and it absolutely killed the low end power. It only helped when reving the heck out of it and during highway passing. I hated it.
So the moral of my long winded story is regear and see what you think about THAT power gain. You may not need to spend a grand on the power package. If you still want more power the proper gears for your tire size will only make it better. It will keep your power band in the "sweet spot" like coyote mentioned.
ive never had any problems with having low end power, not by having a practically open exhaust or the stage 2 racing cam
