Yella Terra Platinum Roller Rocker Set 1.7 Ratio (7/16" Mount, Twin Shaft Adjustable) (YT6640)HOLDEN GEN3 LS 1 1. 7 RATIO Suit GM LS1,LS2,LS6 With GM, AFR, Edelbrock, World, TFS 215 & Dart 205,225 Heads Part Number: YT6640 platinum Race Rockers Designed for the most severe race applications Platinum rockers feature wide body arms for even greaterstrength and resistance to deflection. All platinum rockers feature heavy duty 7 16 mountingsfor unsurpassed rocker stability. Platinum rockers are available in twin shaft versions for parallel valve