to start with suburban and pick up frames are different . also rear axles . the sub started using disc brakes in 2000 . the pick up in 1999 .the disc brakes were not used in 2005 on pickups for some reason. G M engineer said there was not room for them when asked why at SEMA SHOW , even though they went to larger wheels that year . the 1999 and newer has 6 bolt wheels ,and disc and drum brake wheels are different.