ChevyPrincess, I was just about to ask how you like your '08 gaosline, then read further where you said it has problems. I bought a 2006 Duramax with only 35k on it, like new, this past summer. Before I forked over that kind of money for an '06, I test drove three gas engine 3/4 ton Chevys 2008 - 2009 model years in both work truck and LT1 configuration, and didn't like any of them. Hated them, actually. I have a beater '93 Silverado that I like loads better.
Thought the Duramax was the best choice, and would be the longest lasting. My sister has a 2002 DMax with over 225k on it and it's never required an expensive repair yet.
After I bought the Duramax, three guys with Chevy fleet maintenance experience and two farmers told me I was smart to buy it. They all said that the new gassers are shot and run poorly by 100k even if babied and that they expected to have to replace engines by 125k even with good maintenance.
Now, a friend of mine bought a 3/4 ton 6 liter gasoline ext cab long bed 2004 Chevy brand new and has about 40k or 50k on it now. He let me drive it, and it's a delightful truck compared to the new body style 2007 & up gassers. He hasn't had any problems with it.
Whenever you can, I suggest trading the gas for a Duramax, especially if you plan to tow. They are quiet in the cab, they get 16-17 MPG cruising around town, and more like 19 highway with no load. Tuning improves that but I still have the balance of factory warranty on mine so I won't do any mods until after that.
it's so often found the late 90's chevys with 150k or so on them and they're already cooked at least one motor... whazzup with that?
Maybe no fat in the engine design, so it's not really designed to go 200k? They are one of the cheaper engines to swap out or rebuild, esp if you do it yourself and just have parts costs. What kinds of lifespans are people seeing out of other truck gasoline 8cyl engines? Ford has the 4.6 which is fine for a 'Stang but zuck in a truck. And the 5.3, which I can't imagine has much more potential than maybe 125k or so.