2018 GMC Denali swapping to 4.11 Gearing

[DHeinze]

As not to start another string on gearing swaps.... 

I have a 18 sierra Denali 1500 6.2 with 3.42 gears. We pull right up to the max for the truck with our travel trailer and spending a lot of time in Colorado. I have no complaints with the 3.42 gearing until we head up hill 6% grade, there is way to much loss in speed and gear seeking. 

We have found a local shop that will put in the 4.11 gears, but does not do programming. The dealership warranty or not doesn't want to modify it, for the 4.11. Diablo after 45 minutes on the phone told me, yes their T2EX or the I3 would program the truck for the gearing. My problem is I know nothing about programming or do I care to learn at this point. The local tuner shops wont touch it unless it is their brand and they don't have the unlock for the tranny for the 18 models.

So... Anyone in Texas up for some cold beer and some lessons with a Diablo??