I have never had a 8.1 but I recall back then folks talking about how they were diesel like in their pulling power. I can also tell you the Allison is one awesome tranny. The 6 speed tranny is very nice and allowed me to go from 4:10's to 3:73's and actually have a better towing experience. With the 4 speed I was dropping to third on the hills. It did the job though, and I don't recall going much slower than the traffic flow.
I bet with the tools and other heavy stuff I carry, two dogs and us not being know to be skinny, we likely easily had 8,000 pounds. Truck did fine. Makes it's torque at 4400 Rpm's if I remember correctly.
I would also be very leery of the 6 owners. Need someone to look both over and see if anything negative stands out. How many miles on these trucks?
