2006 GMC 2500HD 6.0L / towing?

I've recently bought a Predator programmer for my 6.0L 3/4 ton GMC and have been greatly satisfied with it over it's stock form. My question is that the 87 octane tune I'm running now is perfect for driving unloaded. BUT the added shift firmness at high rpms sketches me out a little bit with towing. I haven't towed with it yet since the Predator tune, but will be towing next weekend. When I click the tow/haul button on the shifter, does that override anything or will it act the same? Basically I need to know if towing with the tow/haul button engaged will be fine with the Predator tune. I figure it won't take long for hard high rpm shifts to take a toll on the 4L80E tranny if towing with it like it is now with the tune.

I also plan to try out the 93 octane tune this weekend as well and see how that does.

Truck specs: 2006 GMC 2500HD crew cab 4x4 6.0L V8 gasser / 4L80E auto tranny / factory 4:10 gearing / FLowmaster exhaust / 20's wrapped in 33-12.50-20 mud terrains / factory airbox

Towing specs: 18' dovetail dual 3500 lb axle all metal car hauler with my rock crawler which is an 84 model Toyota pickup fully exo caged on 39" tires, so I'm guestimating total weight towed (bumper pull trailer) being around 7-8k lbs for both trailer and rig.

[mikel]

FWIW, those firm shifts are good for the trans, slippage kills a trans, and firming up the shifts gets rid of any slippage and allows it to actually run cooler and live longer

You can adjust the pressures for normal and tow haul mode if you like.

Thanks

mikel wrote:

FWIW, those firm shifts are good for the trans, slippage kills a trans, and firming up the shifts gets rid of any slippage and allows it to actually run cooler and live longer

You can adjust the pressures for normal and tow haul mode if you like.

Thanks

Well that's good to know I suppose lol. I wasn't sure about it while under strain of towing. Guess I'll try towing first and see how it does. I'm actually about to swap to the 93 tune in a few short minutes and see what that's about.

I put the "Diablo Tune" in last night, filled up with 93 octane, and drove it around some and been driving today too. I most likely will be switching back to the 87 tune. The shifting in the Diablo Tune doesn't seem as strong as the 87 tune. I guess the 87 tune just feels like a more aggressive driving style (which I do alot of lol). Anyways. Thanks for your help!