I have an 04 2500 hd crew cab 2wd with OEM 245/75/r16 tires. I tow a 3 horse LQ trailers and have noticed the stock truck tires (uniroyal)really bulging out under trailer weight. I would like to get larger tires (Bridgestone, BFG AT) for better traction (265/285?). What size can I safely move up to and will this help with the bulging truck tires (uniroyal). Or is it advisable to move to a larger rim and tire? Thanks

Your stock tires should be 10 ply E load rating. With GM in the safety sticker in the drivers door are the air pressure spec. The rears take more PSI. You can put a step up size tire, but you'll need to recalibrate the odo. www.TireRack.com has some excellent tire info on changing tire sizes.