I know the front wheels arent adjustable but you can align the front wheels with the rears.

Atleast that is my understanding of a 4 wheel alignment. So are the brake hoses getting soft and storing pressure and bulging which is putting pressure on the pistons in their calipers? Would not it do this on both sides and cause premature brake pade wear which I am NOT experiencing. I will have to inspect the frame for cracks around steering gearbox, ive never heard of that one nor even suspected it. But it does make sense. Literally...my truck tears up and idler arm every year! The idler arm will have 3/8" of an inch vertical deflection when pushing in on tire with wheels of the ground. The ball/socket slop is horrible on removal of bad idler arm. These are the moog problem solvers. I have verified the part numbers with moog and multiple parts outlets. Wouldnt be the first time ive had a parts house try to sell me suspension parts for the 2000 up trucks since the 1999 GMC Sierra is a different creature....mine technically is a GMC K1500... But it does say Sierra on it. There were different trucks 4x4 made in 1999. Mine is the "classic" body style 3 door.
Whats this GMT400 moniker? Where did that come from and what does it mean?