I brought them to stock height Chevy 2500 HD, 2003 Duramax with 167,000 miles on stock shocks. Doesn't matter! These are amazing shocks. The movement has become a bit stiffer, much more accurate and fluid. For those confused, these Bilstein 4600 shocks are identical to the Bilstein 5100 shocks except for color, boot style and length. Shock absorbers 5100 are designed for elevators. The inner workings are exactly the same.