[Sabre66]

I have a 4X4 with the Big Tow and my tach runs at 2200 rpms when at 75mph, but that's in 5th gear.

So far it hasn't hung up in 4th gear yet when using the speed control, unless i'm heading up a grade. Then it holds 4th until we reach the top of the grade.

I have noticed that going down steep grades it sometimes downshifts to slow the speed of the truck, but i assume that is just an "engine braking" feature taking over.