Okay. Looks like the left rear tire on my '87 1 ton has a belt seperation (I found a bubble in the tire by accident). It also has C load rating tires which aren't sufficient for the new 5th wheel we just bought which weighs over 8,000 lbs. empty. Right now it has what I'm pretty sure were the stock size tires for it, 265/75R16, which are 31.6" tall according to the calculator (and if anything, they're shorter in real life). I'm going to step up to a set of rear tires that are D or E load rated. I am thinking of going taller because this thing has no overdrive and it's really rough to turn that many RPM unloaded. The only thing is, I want to be sure that I'll be able to pull my new 5er just as easy as before. It'll drop from 3,200 RPM @ 65 to about 3,000 if I have 4.56s, and 3,000 to 2,800 if I have 4.10s (I'll know by the end of the day, I'm pulling the cover). So, if you were me, would you step up to a set of 33s in the rear, or stick with the 31.6" tall 265s? They'll be E load rated 80 PSI tires anyway, so, would you go a little taller?