While I have all this great attention, I'd like to ask, are there some good threads to read about AFM/DOD delete, Z95 suspension repair or delete, and spare tire usage on the AWD models? My current engine is strong but it's starting to let exhaust manifold bolts go. I'd like to get a used motor and do the delete myself and drop it in once she get a little more clapped out. My front struts are bouncy and I'd like to replace them with Z71 style ranchos or bilsteins but not sure of the impacts on the Z95 megnerides. And my truck has stock 20s and the spare is an 18. Want to know if it's safe to use in an emergency with the AWD or if I'll blow the differential out with the size difference. Suggested reading material is appreciated!
Keep the Z95 suspension. Replacement GM or Arnott rear air ride and front mag ride shocks are relatively inexpensive on rock auto (compared to dealer prices), as is the compressor if it needs it. We've seen folks go to regular shocks and regret it, going back to the factory mag ride/air ride setup. It's an incredibly effective and reliable system.
On the spare, if you run the calculations, it has the same diameter and circumference as the 20" wheels and tires, so it's safe to use in a pinch. I replaced my spare on my '07 with a new tire because the original was 16 years old at the time and I didn't trust it if I ever had to use it on a trip.
Exhaust manifold bolts are easy fixes when you come at them from the side after letting them soak with penetrating oil overnight. If you break any or can't get the stubs out, they sell a drilling and extraction template on Amazon that works great so you don't damage the cylinder heads.
Lots of threads on here with advice and learnings for AFM/DoD delete. I'm running a Cam Motion Stage 2 truck cam (3-bolt) in my 2012 XL Denali that I love.
Only other things I would recommend is 1/ only running premium fuel in that 6.2L, and 2/ replace the torque converter with a billet unit that has a stronger lockup clutch. And, 3/ Get that thing Blackbear tuned! Some of the best money I've spent. It will wake up the truck, make the transmission last longer, and they can tune out AFM, too.
