I have an 06 duramax PU, crew cab. I got an 04 WW fs3000 about a month ago and I was wondering if my tires are up to it, I have 305-50-20's xl rated at 3085 per tire, the load range E tires 305-55-20's are rated at 3180 as well as the stock 245 75 16's that came on it, am I ok with these tires? I see only a 95 lb load rating diff between them but the E's use 80 psi and my xl's use 65 psi, I'm guessing there is a sidewall difference as well, the rims are rated over 5k.