Engine Oil Pump Relief Valve Shim Washer

1x Oil Pump Relief Valve Shim Washer

Will Fit all 10, 11 & 12mm Subaru EJ Oil Pumps

Genuine Subaru 031106000

10mm use 2 shims from the factory
11mm Uses 1 Shim from the factory
12mm uses 1 shim from the factory

Adding 1 shim over the base oil pressure shim can see up to 4% increase in oil pressure throughout the full RPM range