Unless the parts are relatively new I would replace the pitman arm and the idler arm. I replaced mine years ago, but still had some play in the steering. I drove it that way for 100,000 miles. I finally adjusted the box and that truck has never drove this good since it was (almost new) to me. I...
Elevation is a major performance hit on the motor, but you will see a huge difference when you get the BB tune. Have them remove all of the torque management, increase the timing and maybe increase the demanded shift RPMs. GM has it programmed to remove most of the timing 10deg btdc, when it...