The stock tune is for all 6.0 engines...a custom tune is for your specific vehicle. The tune can remove TM, but you can ask to not remove it. A custom tune will make your engine run more efficiently. I dont have the 6.0, but my little 4.8 runs a lot better with the custom tune. Transmission shifts much better as well. I had Wheatley remove 50% TM in regular mode and 100% in Tow Haul. Not much difference in shifting between the two.

 

I just recently sold my 2500HD ECSB, 6.0L, 4L80e, 9" lift and 35" tires w/ 4.10's.

They're big, they're heavy and they're slow. But ****, they'll pull whatever you put behind them. I think you may be feeling the taller 1st gear in the 80e off the line, it definitely isn't as short as the 60e 1st gear.

 

Tires now are 285/75 R16's (32" tall), I know this is the biggest problem I have. As soon as they get wore out I will be getting something shorter. The weight of the camper flattens out the tires out a little causing more power loss. I think the gears are 3.73's, don't know how to check. Headers are short tubes.

 

I used to run that same size tire (they're actually 32.9", you could basically call them a 33 ), and they're killers. My 60' times sucked for sure, even after a cam and tuning, which was good for a .9/8mph improvement, I was still cutting 2.5 sec 60's I have 3.73 gears also. When I lowered the truck and swapped on 31" tires, I was able to launch again lol. Haven't been able to get back to the track to see the improvement unfortunately, but it's definitely there, especially in the winter when I remove these heavy JGP 20's and swap on my factory 16's with some 275/70's.

 

Your best bet is to pick up a used supercharger from here in the classifieds section, and also get a custom tune, get a shift kit and a big tranny cooler and you will love the new found power, you will definately enjoy pulling the fifth wheel then, or do like me get rid of the gasser and jump into a duramax and enjoy the pulling without worries