My buddy has a 2005 Chevy Duramax crew cab dually that he is thinking about selling because he is moving out of the country. It has 115,000 miles on it with about a third of that towing a 38 ft. fifth wheel and an 18 ft. boat, (not together,seperately). It has a five speed allison, an edge juice on it and four inch exhaust with aftermarket intake. He has offered to sell it to me, and I know he will give me a good price, but I'm a little concerned about the cost of an engine or trans rebuild if becomes necessary. He drives it hard but has never had any problems with it. The thing is a beast when it comes to towing, very impressive. His son is a mechanic and does all the maintenance on it, which includes synthetic oils. So what do you think, should I jump on it. Any problems with the '05 duramax's/allisons. Any advantages or disadvantages compared withn the newer models with the six speed allisons.