Thanks for your thoughts guys. I'd really like to go with the 6.0, but I'm not sure it would get that much better mileage. It would probably be a lot more enjoyable to drive, but it would probably not be too appreciated by the wife who usually drives that vehicle anyway. The thing has always been a real dog compared to my Z66 Avalanche with the 5.3, and that hasn't bothered the wife. If it were my daily driver, I would try to tackle the 6.0, but Redheartbeat's comments about women in general definitely apply here, and I'm going to be gone for several weeks for work at the end of July into August and I'd better have her back on the road before then, and I'm also super busy at work leading up to this business trip.