I have the shorter Radflos and I have them set to give about 2.25" of lift, problem is I am not to happy with the ride quality. I am considering using a 3/4" spacer and reducing the preload by 3/4". I took my TGC Spacer over to a local machine shop and they are going to use that design and Waterjet cut me a set 3/4" thick. My problem is I was searching here and saw the ones that PRG has and they are cut like the top plate of the Coil over. Is that design needed or will having the inner hole diameter at 2.5" (circle) be able to clear it. In the end, I think I screwed up and should have just bought the 3" version and the TC UCA, and kept the preload low, because I'm feeling like I am headed towards purchasing that UCA anyways, I'm afraid once I install the spacer and reduce the preload I will have more downward travel giving me the dreaded UCA contact all over again. But hey, in this hobby, we have to assume all risks physically or financially.