You can get over the tire/wheel thing with a set of newer takeoff 18 or 20" Ram wheels (idk if GM made any 18s before they switched lug patterns). Beef up the suspension, make sure them 24 year old brakes are top notch and haul your combo in relative safety if you trust the condition of the truck.
But that 6.5 will still suck wind worse than a _____ with no front teeth. I know my way around those engines and they're a bigger abomination than 6.0 and 6.4 Powerstrokes with half the power in their stroke.
