02 Screw, 4x4 with P255-70-r16 stock tire.
I am looking for an LT or 6 ply rating tire that has higher load rating, and very nearly the same diameter without going to a higher profile, increasing possible sway while pulling a trailer.
A search seems to show this is hard to accomplish.
I need to preserve gear ratio by not going larger in diameter and still get a higher load rating.

 

I just did a quick search and found 3 tires that fit what you are asking. That is looking at BFG and Goodyear only. BFG AT, Long Trails, and Goodyear AT/S all have LT255/70R16 load range C or D. I am sure in that size you could also probably find them at Bridgestone, Cooper, and others.