4.000" - 4.060" Bore Piston Oil Ring Rail Spacer Support (0.020" Thick) Speedmaster harmonic balancers are crafted

Speedmaster harmonic balancers are crafted from high-quality steel and feature a tuned elastomer for optimal engine performance

Providing performance and style with its polarized lens reducing glare reflections from mirrors

It is set up to accept a spread bore carb

Impala and Buick Roadmaster

4.000" - 4.060" Bore Piston Oil Ring Rail Spacer Support (0.020" Thick) Speedmaster harmonic balancers are craftedThese 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.