yep,
know the sound.. I was pulling about 16-17k for the last 1000 miles I heard a lot of that - out I-10 from the hill country - way west Tx.. & back..

Mike - the 87 Perf/tow tune seemed to work flawlessly..

Got to empty last night and filled with 93 on top of about 2-3 gals of 87 - got home and tuned to the 91 perf/tow - drove about 200 miles this am & it felt pretty good - overall with the 3.73's at highway speeds the 6.2 will rock..

Even with the heavy trailer (btw I know that I was loaded heavy - some might think overloaded - but we have to do what we have to do..) this 6.2 will pull!