Ok, here's my post from a prior thread on this issue, worth repeating:
I'm in the same boat. I want to ditch the 65MPH rated ST tires and go with an LT that can safely do 70 or 75. The problem is, my current ST 235 80-R 16 tires are rated at 3400-3500# (depending on brand,) but to get that weight rating in an LT tire, I need to jump up to a LT 265 75-R16. I don't "want" larger tires (about an inch, in this case,) but I have to in order to get the load range/rating that I need. They don't make a 235 or 245 LT that can carry that much weight.
Something else to think about before plunking down any cash on LT tires--check the weight rating of the size you "think" you want.
2015 XLR Hyperlite 30HFS5 (mods being performed regularly)
2009 Salem LA 292fkds (gone)
Nights- ('12)23 ('13)23 ('14)15 ('15)31 ('16)25
2014 Harley Davidson FLHX (XLR cargo)
2014 VW Jetta TDI (diesel sipper, camping support vehicle)
2011 Ram 2500 CC 4X4 CTD, B&W Companion (toy hauler hauler)