I don,t buy that you should have to slow down to 5mph to cross a set of tracks.I bent my passenger control arm after hitting a manhole cover.Ihad 2 inches of clearence.This is a safety hazard.I now have everthing stock with 2 coils cut.By far much better.Now if you like 20 in wheels spindles may be better.I have 15in. ralleys on mine.I'm not an expert.This is my first fullsize chevy truck,but I have built many muscle cars(camaro's, chevell's).My personal opinion is that I know you will give up something when you lower a vehicle.I think just cutting 2 coils works best.I am always looking for something better but hav'nt found it.Not into air bags either.