I've had the 1" GM level for about 3 years. I had it installed by the dealer at the same time I had them remove the air dam. I can't find before and after photos, but it did eliminate most of the rake. However, when I installed a rear add-a-leaf this spring (to account for the extra weight of a shell) the rake came back (of course.) I don't hate having some rake, but I'm replacing the GM 1" level with a 2" ReadyLift level tomorrow to get it back closer to level again.