stock tires and wheels

[IRA51]

I bought a 2003 H2 and it has 22 inch wheels and low profile street tires.I would like to do some off roading and would like to know if there is any advantage to going to 37x1250-17 tires on 17x10 inch wheels over the stock 8.5x17 inch wheels and 315/70-17 tires .I don't plan on lifting the truck but will put the Fabtech hd tie rods on it . I have been told the 37/1250-17 tires won't rub on it. if anyone who has any experience with this let me know B4 I make the purchase . I have the stock 17x8.5 h2 wheels but no tires and if I use the stock wheels I was planing on useing the BFG at ko's in 315/70x17 unless there is something better. any help would be greatly apresheated .