The Lift
Actually the 2" lift and subsequent reverse rake has nothing to do with the Allison, The Duramax is a tall block truck engine and is physically 2" taller then the gas 6.0L.
We raise the nose 2" to line up the fan to the fan shroud, this equates to 1.5" over the front tire which ironically is the exact forward rake GM puts into the SUV that we all hate and buy leveling kits to get rid of, So in the end you get a nice level look on our finished product.
Rear Diff Options
The 2007 SUV's came with a 9.5 semi floater, it is fine for towing within the factory limits of the bumper receiver (10K) and if your SUV is 2008 or newer it will come with the 10.5" full floater rear diff, if you don't intend to pull more than 12K there is no need to swap it out but if your going for the max (aka TowPro edition) then you receive the 11.5" P/U rear diff / braking system and ABS system.
NOTE> When you opt for a TowPro the SUV moves up to the Factory 2500HD P/U Stance, this is due to the fact that the rear diff has 1" taller spring perches as well as 1/2" larger axle tubes, we turn the torsion bars up to match
We also offer a 17K capacity ridged frame mount receiver for legal and safe higher load towing as seen here
17K OptionBrake Upgrades
Yes we do offer Upgrades, we use Wildwood's TC6R 6 piston calipers and slotted & Cross Drilled rotors pt#140-9406-D rear and pt#140-8996-D for the front
Sorry you were mislead on the whole brake thing, should this info change you're mind feel free to drop a call to DuraBurb Sales @ 407-257-9657
Eric Swanson
DuraBurb Service Dept