Valve springs with larger diameters require retainers to handle the higher pressures developed by the springs. COMP Cams Steel Retainers are the perfect solution to this problem. COMP engineers used 3D CAD with FEA to design retainers with a modern and advanced contoured top profiling for lower stress increased lift and a reduction in mass. The retainers are CNC-machined to exact tolerances using CAD/Cam software. All COMP retainers use only high-grade SAE 4140 chromemoly Steel with no lead <0.04% sulfur and a black oxide finish to prevent corrosion. COMP Cams Steel Valve Spring Retainers offer both unmatched looks and superior performance that set the industry standard. COMP Cams Part# 712-16: Includes 16 Retainers. Buick 350-455 Steel Retainers. 10° Lock Angle - 11/32" Valve Stem Sizes - 1.225" - 1.250" Spring Diameter.