We have 2 NEW Wilwood 6 Piston Right Hand & Left Hand Billet Prolite 6R Calipers 120-5598 & 120-5599-FS. The bolt pattern is CLOSE TO 5.250". For 1.380" Rotor. This is a very expensive item. Recycling one ton of cardboard saves over 9 cubic yards of landfill space.