I have been towing an 18ft TT as well as having an 800lb.Quad(ATV)in the bed all over the mountains of Arizona and Utah, 8-10,000 ft. altitude, with a 250 cid 1/2 ton GMC. It was painfully slow going up when it was stock. Now... I have put a cam, headers, good intake, duel point ignition, and a Sag. 4spd in it the old truck seems to like that much better. The 4spd added some mid range and the rest added some RPM's I also have a 99" Dodge RAM with the 5.7 motor but I still love dviving the GMC better. More fun you understand.
Drive on...
DD
