You should be aware that the term "acceleration", as applied to the 2nd and 3rd generation 4Runners should be, instead, "Gathering Speed".
In both cases, the basic physics of the situation is that a heavy vehicle propelled by a small-displacement engine won't yield jet-like acceleration in any event. Even the 3.4 supercharger will do no more than mildly boost performance.
If you must have 15-sec 1/4 miles, give it up and buy a 4th gen V-8. Attempting to squeeze a quart out of a pint is sure to dissappoint, one way or another.
Good luck!