my pre runner is super light with 35s and it just floats across the mudholes! hahaha i make those big 4x4s look pathetic. im 2wd and i get through more gnarly stuff then chevy silverados with 38s, and i got the 4.0 with flowmaster,, hallowed out cats, cold air intake, and chipped for more power, my bed is removed, all four fenders were replaced with fiberglass, as well as the hood, took off the front and rear bumpers cuz theyre heavy. swapped the rear axle out for a geared 86 ford 8.8 with detroit locker,the truck is super super light, ive got a 6 thousand dollar suspension system in it, beefed up the power a bit and i kick everyones booty in the mud,sand,and trails and i still get 32 mpg! for real!
what upgrades should you do? sounds like you wanna build it for a mudder, do a lift with 33s or 35s, and 15 inch rims, put bushwhacker bolt on fender flares, they look beefy and mean, as well as make you legal with big tires. Put a roll bar in the bed with offroad lights mounted on top.Then on the slants that brace the roll bar for strength, mount a spare 35'' rim and tire to your slanted part of rollbar.....takes away room in your bed, but if you do it right you will still have room for a dirtbike, or a atv if you rest the front atv bumper ontop of the spare tire,so the atv is resting on the back wheels and tie it down so it dont fly out of truck. thats a few ideas, they go on with bumper designs, stripping weight off the truck, to compensate for the bigger tires, inside roll bars, fog lights on front bumper, skid plates under frame, rocker sliders to protect cap, and so on and so on....lol if i keep going youll have 20k in upgrades hahahah. thats my cool idea for a mudder.
oh and for power to turn the big tires without spending big buccks on a 302, do all the little upgrades like hallow catylitic converter, flowmaster, cold air intake, super chips, shed the extra weight in the truck, and also change the gearing and add a locker. hope this helps! have fun!!!!!!!