I have 4 piston Wildwood on my Hadrtop, and 4 piston Kelsey Hayes on my Ragtop. My Ragtop was converted to BBP 1974 Factory single piston when I bought it with 100K. I put 100K more on it and only maintained wheel bearings and pads. Same rotors and Calipers . I thought they worked real good , parts are cheap, three less Calipers to deal with, less $ to deal with. More wheel options 4.5 BP . I just coverted back to KH small bolt patern for Stock look. JMO