WILWOOD Rotor HD48 SPC37 RH 11.75 x 1.21 8 on 7.00 160 13497 eBay Wilwood Rotor GT48 SPC 37 LH 12.60 x 1.29 12 on 7.00in eBay Wilwood Rotor GT48 SPC 37 RH 12.72 x 1.38 12 on 6.75in Kies Motorsports Wilwood 160 13543 BK Rotor SRP48 SPC 37 RH BLK Drill 12.88 x 1.10 12 on Wilwood 160 12892 GT 72 SPC 37 Straight Vane Rotor, 11.00 x .810 Inch Wilwood 160 12284 Rotor HD36 SPC 37 LH THMotorsports. SRP Drilled Performance Rotors feature a specially engineered directional cross drill and face slot pattern that improve brake response and pad performance throughout the entire range of light to heavy braking. The venting and cleaning action of the holes and slots will reduce pad glaze and disperse gasses and heat generated during the pad to rotor interface. The holes and slots also inhibit irregular pad compound build up on the rotor faces resulting in smoother engagement and improved pedal response in all conditions. The material removed also contributes to lower rotating and unsprung suspension weight.