Wilwood Disc Brakes Hat (Bell) Mount Rotors Wilwood Rotor GT48 SPC 37 RH 12.88 x 1.00 12 on 8.75in Walmart.com WILWOOD Rotor HD48 SPC37 RH 11.75 x 1.21 8 on 7.00 160 13497 eBay WILWOOD Rotor HD48 SPC37 RH 11.75 x 1.21 8 on 7.00 160 13497 eBay Sell WILWOOD 160 8399 Rotor 12blt 1.25 x 14in L H Dirc GT72 in North. GT 72 straight vane rotors provide high value performance and rugged durability for a wide range of competition, high performance, and sport driving applications. Don't confuse these rotors with bargain priced off brand named parts. Wilwood's modern manufacturing capability, combined with large scale economies, make it possible to offer this level of quality and performance at such an affordable price. Coupled with Wilwood's exclusive Spec 37 material, a proprietary iron alloy developed to withstand extreme temperatures with the highest possible degree of resistance against distortion, warping, cracking, and wear.