I know what you mean about the Crewcab, that was on my list of must haves when truck shopping last Summer. With 3 boys in the back the extra room is much appreciated! I hope you can get it straightened out, could be something simple. As others have said some of these engines were bad but many more of them were very good so you may be just fine and dandy in the long run!
2004 Chevy 2500HD Crew Cab 6.0l, 4.10r
2010 Jayco Jayflight 28BHS
Reese Strait Line with Dual Cam
P3 Brk controller