PAC Racing Springs Valve Spring Shims - 0.020 in Thick - 1.250 in OD - 0.570 in ID (Set of 16) 12731654 1978-1987 Pontiac Grand Prix CID

1978-1987 Pontiac Grand Prix CID 327 RWD

Rib Protector

Landrum Performance Springs are made with the highest quality US made High Tensile Chrome Silicon Alloy Steel for strength and reliability

Air bleeds moved outward to allow a smoother transition of airflow

Pre-1987 Mustang

PAC Racing Springs Valve Spring Shims - 0.020 in Thick - 1.250 in OD - 0.570 in ID (Set of 16) 12731654 1978-1987 Pontiac Grand Prix CIDProduct Description: Valve Spring Shim 0. 020 in Thick 1. 250 in OD 0. 570 in ID Steel Set of 16 Traditional Springs are made from the same size (Diameter) wire throughout the helix of the spring. PAC Racing Springs has partnered with technology leaders in order to provide this advanced new tapered wire product. Tapered wire allows for a true progressive and dual rate without reducing spring travel and increasing weight from traditional methods.