4.290" Bore Piston Oil Ring Rail Spacer Support (0.030" Thick) Set of 8 Speedmaster valve guides are constructed

Speedmaster valve guides are constructed from high-quality bronze for durability and wear

2 SFI Approved and will withstand the extreme power and rpm of your performance application

Fits big block Chevy rectangular port cylinder heads on standard deck blocks

The next level of performance are these cast-iron Chevy LS blocks

for the Ford Coyote (2015-2020)

4.290" Bore Piston Oil Ring Rail Spacer Support (0.030" Thick) Set of 8 Speedmaster valve guides are constructedThese Speedmaster piston oil ring spacers are used in applications where the piston oil ring groove intersects the pinhole. Speedmaster piston oil ring spacers are manufactured from spring steel and install against the bottom sill of the oil ring groove. Available in different bore diameters to suit your specific engine's needs, the Speedmaster piston oil ring spacers will keep your pistons working smoothly throughout the entire operating range.