Ahhh, you have the 4.88s huh? i got the 4.10s. and I run on 35.5 inch tires. I dont hit 2000 rpms till 68 mph. And the hills I hit are across I-10 in the pan handle of Florida. Nothing too steep, but I would say 5-7 % grades, and they last a good bit. Nothing like the hills of Wyoming on I-70.... but still pretty long ones. the ones that made me downshift, were the steep short stretches, like over-passes. I still stayed nice and cool, on either tune, but with the STREET tune loaded, the MPG def got better, and no more downshifting!
BTW, you were absolutely right about the SRW towing! lol! Across Florida with 0 wind, and light to no traffic, A-OK. But last Sunday, 95 South along the coast of Florida.... 40mph wind, kicked my AZZ! lol!
I never doubted that a dually was the way to tow heavy, but I knew the SRW would do it. And in perfect conditions, I wasn't wrong. But, I didn't think that it would be as bad in inclement weather...
And now that I am not buying a house in Florida, I am shopping for a 2010 Harley Davidson F450! lol! I wanna keep my SRW for daily driving and play time, and use the dually for what a dually is made to do....