Comp Cams Rocker Arm - Ultra Pro Magnum - 3/8 in Stud Mount - 1.80 Ratio - Full Roller - Chromoly / Steel - GM LS-Series - Kit-16755-KIT--Notes: 1.80 Ratio, 5/16 guide plates. State Restrictions- Canada Restriction-NO -Emission Warnings--NO Truck Freight ---NO