Ok, I've been wanting one and finally pulled the trigger. I just picked up a 99 2500 Laramie with 4 wheel drive, Cummins power, ATS transmission and Co Pilot, tuner, and yes...a 53 block. Yep, taking some chances on this but it only has 180k on the clock and one owner, and it's in immaculate condition so WTH!! I just finished a 300 mile round trip with it last weekend, not towing, but the trip computer showed an average of 25 mpg, which is better than my son's Tacoma, so I'm pretty darned stoked about it. I'm looking forward to a long and happy relationship with this one!