.047 Spacers - SBM R/A Shaft (4pk)

The .047 Spacers – SBM R/A Shaft from SHARP ROCKERS is a precision rocker arm shim set engineered for small-block engine builders and performance mechanics who demand exact valve lash clearance. This four-pack of steel spacers, each measuring 0.047 inches in thickness with a 0.875-inch inner diameter, delivers the critical dimensional control required during engine assembly and fine-tuning. These shims work within the rocker arm shaft system to establish proper clearance between rocker arms and valve components, ensuring consistent valve operation across the entire RPM range.

Manufactured from steel for durability under sustained mechanical loading, these 0.047-inch spacers integrate seamlessly into small-block Chevrolet and comparable aftermarket rocker arm assemblies. The precise thickness specification is critical—incorrect lash clearance leads to incomplete valve seating, reduced compression, and potential valve float at high RPM. With four spacers included per pack, builders have flexibility to distribute shim thickness across multiple rocker positions or consolidate clearance adjustment at specific locations. The 0.875-inch ID accommodates standard rocker arm shaft diameters, simplifying installation for experienced engine builders familiar with small-block geometry.

These spacers serve builders, machine shops, and performance enthusiasts undertaking small-block engine rebuilds, high-RPM street builds, and race engine assembly. Whether fine-tuning an existing engine or commissioning a complete build from a core, the ability to adjust rocker arm geometry with precision shims is foundational to achieving reliable valve timing and preventing mechanical interference. Engine builders specify rocker arm shim thickness based on measured clearances taken during the assembly process, making incremental packs like this essential to have on hand during final valve lash setting.