Rockers

Valve Springs 1.355 (Set of 16)

• Single 604 Crate Motor Cheater Single Spring
• Outside Diameter 1.355
• Outer Spring ID 0.910
• Install Height1.750
• Load at Installed Height 125lbs
• Spring Open Height 1.250
• Spring Open Load 315
• Recommended Valve Lift 0.550
• Spring Rate (lbs/in) 380
• Coil Bind (max) 1.180

Main Bearing B18A/B (Standard)

Valve Springs  0.630 in. ID – 1.274 in. OD – 1.800 in. installed Height – 0.750 in. Max Valve Lift (Set of 16)

PAC Racing’s RPM Series Dual Valve Springs  #PAC-1238X are constructed using our signature PACaloy super clean wire and are heat-treated in-house for precision spring rates and improved strength. They also receive a multi-peen process, polishing, and a Nano-Peen™ proprietary surface treatment for service life optimization. These springs fit GM Gen III/IV LS engines with specific part numbers for stock heads and aftermarket heads.

• Built using our signature PACaloy super clean wire to ensure strength and durability
• In-house heat-treating for precise spring rates and increased strength
• Multi-peen process to optimize service life
• Polishing to improve operating cycles
• Nano-Peen™ proprietary surface treatment