I tried the lower 1.5" spacer and it did push the shock against the cv boot. I went with the pro-comp top mount 1.5" spacer and it has been fine. My truck now sits level according to a level I put across the bed rails. My front fender well opening is 39.25", the rear fender is 28.75". The truck seems to have sagged in the back a little, truck is 5 months old. I say this because after I installed the 1.5", I was thinking I should have went with a 2" lift, but after the little bit of sagging rear I'm happy with the 1.5".