Wheels in and mounted up! Pretty happy with most of GM's layout. The only restriction is going to be the body mounts. They are gigantic! Can't believe they mounted up without having to cut anything. lol
So the package is:
RockStar II 17x9 with 4.5" Backspacing / -12 Offset
Hercules 35x12.5R17 They measure a true 34"
This looks like it will be the max. Truck goes to body shop next weekend for body works for clearance.
Rear: Looks like back edge might kiss with a load so I will have them roll them 3-4" up just to make sure or in case I ever do a solid axle swap down the line 37"s will clear.
Fronts: The bumpers are completely hollow, and I'll be removing mine anyways in favor of a Tube Winch Bumper like the one I built for the Yukon above. I'll have to have someone build me some moldings for the sections under the head lights to retain a straight line so there will be no gaps between the bumper and headlights.
The major work is going to be to the kick panel quarters. The only restriction is going to be the body mounts which are so large they almost come out past the start of the kick panel firewall. I'm pretty confident that my body guy will be able to get everything all the way back to that leading edge without an issue and have plenty of clearance for this size tire.
On the inside, the tire and wheel clears the knuckle easily. Tightest point at the top is 1.75". So people can run 13.5"s with this offset or run a 5" backspacing with a 12.5" tire, if they like the tires all the way inside the fenders. The every other recessed tread lug is within the outer most point of the fender which is the max I am comfortable with exposed to keep the police from hassling me.
I'm sure some might have questions but here are some pictures.