tatest wrote:
Nothing you did towing would have an effect on the engine's valve train. So towing didn't break your truck.
Valve train problems don't mean you need a new engine. Lifter problems are a lot more likely than camshaft problems, and can usually be taken care of with the engine in place. I've pulled cylinder heads for valve jobs and replaced lifters and pushrods in the driveway. We've also replaced camshafts on this engine type without pulling the engine, but if it is gone that far it may make more sense to pull it for a rebuild. There are a whole lot of things cheaper than buying a new engine.
Whether or not an Avalanche is adequate for towing a given load, or a 2500HD might be better, has little to do with the engine. What the 2500HD brings to the picture is a chassis to carry a heavier load: frame strength, springs, shocks, axle, steering gear, tires, wheels. If you have found the Avalanche adequate in this respect, it is adequate. A heavier truck might feel better, it might not.
Being a Ford guy, and having no direct experience with this generation of Chevy engine, I don't know its particular problems. I do know that the 6.0 in the 2500 is the same engine as the 5.3, and if this generation Chevy small block has valve train problems at 100,000+ miles, the 6.0 will be as likely to have them.
If you want to buy a new truck, wearing out the engine on your old one is as good a reason as any to buy one. Just remember that you'll either have to fix it anyway to sell it, or take a hit on the trade-in value. I am pretty sure the dealer will deduct the cost of an engine replacement, whether or not that gets done before the trade-in is sold.
The 6.0 engine is not the same engine as the 5.3. The 6.0 is a truck engine without cylinder deactivation and is pretty bulletproof.
