4.530" Bore Piston Oil Ring Rail Spacer Support (0.030" Thick) Set of 8 Speedmaster billet main caps are

Speedmaster billet main caps are precision CNC-machined from superior-quality 1025 billet steel

These Speedmaster aluminum crankshaft pulleys help to increase horsepower by reducing accessory drag

Speedmaster remote thermostat housings locate the filler neck at the highest point of cars with low mount radiators to bleed air

which are each sold separately

4.530" Bore Piston Oil Ring Rail Spacer Support (0.030" Thick) Set of 8 Speedmaster billet main caps areThese 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.