I just did the autoride delete and 2"/2.5" lift on my 03 Denali with 225k SD rust belt miles and it was pretty easy.....and I would have to classify my undercarriage as very rusty. Took me 4 hours to do everything. The rear air shocks and OEM springs replaced with Z71 springs and a 1" spacer, as well as Bilstein 5100 shocks. I "rented" GM torsion key tool from O'Reillys which means you pay for it up front $90 but you get all $90 back when you return it. Removed the front shocks, unloaded the keys, and after few convincing whacks with a BFH and the old keys were out and the new keys were in, also added Bilstein 5100's up front. I soaked everything in PB blaster for 2 days before I worked on it (literally soaked, pretty much used a full can). Started it at 9 Thursday night after the kids were in bed and crawled into bed about 1:30 AM. New tires went on Friday AM and part of the tire quote was a full alignment. Rides and tracks great but will keep an eye on my tires for uneven wear until I know I can trust the alignment they did.