bumpstops do affect ride height. if the rod is sitting lower than the stock height by a good amount, the bumpstop prevents the shock from traveling all the way down. when you install h&r and eibachs you have to cut the bumpstops in half. even the directions say. my eibachs sat with about a 2 1/2 finger gap before i cut the bumpstops. then when i cut them they went down to just above the tire to its proper 1.8" drop instead of a 1.3" drop.