1.263" Od. 0.510" Id. 0.041" Thick Hardened Steel Valve Spring Seat LS1 Your street rod or show

Your street rod or show car deserves the very best

These Performance Automatic hardened input shafts are custom-forged from 9310 non-twist steel

Speedmaster billet main caps improve reliability in highly stressed engines by reducing distortion of the main bearing bores

These Speedmaster alternator brackets are constructed from billet aluminum for durability and can be used with several different alternators

this high-performance oil pan is fabricated to meet the demanding needs of top fuel and alcohol applications

1.263" Od. 0.510" Id. 0.041" Thick Hardened Steel Valve Spring Seat LS1 Your street rod or showAs with all other parts in the valvetrain, the area where the spring sits takes a beating. The old standard shims simply will not hold up to the extreme pressures and high rpm found in today's performance engines. Speedmaster offers this set of valve spring shims to solve this problem and eliminate failures.