I was just going to mention that too. You hear your rear end? I hear nothing from the tranny or the rear end at any speed. In the lower gears there is a small whining that I think is normal.
It is engine RPM that limits me from going faster. I think I cruise at 50 but have hit 55+ pulling into traffic, but just don't like all those RPM'S for sustained periods.
I saw your truck the other day and your tires are much taller than mine so I am probably doing a few more RPM than you at 50mph.
