Woudn't take much to get some 33"x9.5/15 Super Swampers in there.
The narrow width was specifically designed for Wranglers with stock rims.Quadratec has them.

Simple 2" suspension lift would clear them without spending much.
The Jeep inline six will push narrow 33's.
Wranglers were never meant to be fast anyway so losing some power may not bother you.

Hopefully you have the tow package with 4:10 gears and a Chrysler 8.25 or Dana 44 rear axle.