Who has a camper with a slide on single wheel truck

Got an 02' 2500HD Silverado,6 ltr. gas.4.11 rear end.Pull a 25 ft Wildcat 5th.Drove it to Alaska and about 40,000 mi.across USA.No problems until we got into MOUNTAINS.Around Mich. all is fine,but I wouldn't take it into the Mountains again.Goin up AND comin down pushes it to the MAX.Over 11,000 ft in New Mexico and it was still pullin,but not happily.DRW or SWR,if your gonna do mountains - take a Diesel!!!