What's the axle ratio? Should be 3.73 or 4.10, GT4 or GT5 on the glove compartment sticker. I "think" the tow ratings were 12k/16k depending on ratio - obviously plenty of pull there.

Sold my '01 Yukon XL with 189k on the ticker. Only thing it needed was tires. I could swear there was a bulletin that called for replacing the intake manifold bolts to cure the oil consumption issue.

Congrats on your new boat. Awesome cat!

The 8.1 Allison packages have the same tow rating as the Dmax trucks and the rear axle ratio did not matter. The gera ratio only changes the tow rating with the 6.0 trucks. My 01 had 3.73's and my 07 has 4.10's.. The 01 actaually got a about .5 mpg better when empty than my 07 does.

I had an '01 Chev 3500 8.1 with 6 sp manual. 127,000 miles. It burned oil a lot! Towed a Baja 302 like it wasn't there. Pulled real hard. I didn't like the manual tranny. Once it was warm, the clutch wouldn't come off the floor. Had it inspected and Chev couldn't find anything wrong. I installed a spring to bring it back up and I had to pump it to engage the clutch. Must have been a hyd leak or something. Other mistake is it was a 2WD. After not being able to pull it out of Lake Cumberland in the rain, I sold it fast. I think the 8.1 pulled as well if not better than a 2001 Dodge 2500 Cummings I had.