I am almost ready to do the lift on my '05 2500HD. I am going for a 6 inch with 35x12.50x17's (muds)
My concern is the tranny, rear end, etc. Are you guys having to do any other mods after the lift? I don't want to re-gear a brand new truck.
I know the Allison is all digital, do the 35's screw that up?
I love the truck the way it is, it is just too low for me. I don't want to screw up the ride or any of the things that I love about this truck.
Input???

Hardly even notice any power difference with 35s. If you were towing heavy you might need lower gears, otherwise don't worry about it. Transmission doesn't seem to care either.. You will want some Superdiesel tie rod sleeves and Cognito idler and pitman arm supports. Order 2 sets and send one set to me. ;)

15,000 miles for me so far and no problems.

no problems here either. about 15,000 miles too. I installed the tie rod sleeves from SD but havent gotten the centerlink. Ive got a one ton though and its got a 4:10 rear end.

37's with 6" lift...25,000 +...No problems...Been in the air otr quite a few times. Got rid of the wimpy tie rods after I bent them. Just keep an eye on your front bearings...not the best built part on a DMAX.