Nylon Needle & Seat Washers (10pk)

The Nylon Needle & Seat Washers (10pk) from Advanced Engine Design are precision gasket components designed for carburetor fuel delivery systems, particularly Holley carburetors used across street rods, classic muscle cars, and performance engine builds. These washers form the critical seal between the needle valve and seat, preventing fuel leakage and ensuring consistent fuel pressure regulation. Any serious engine builder or mechanic knows that carburetor internals demand OEM-grade replacement parts—cheap knockoffs lead to flooding, stumbling, and wasted fuel delivery tuning.

These nylon washers measure 0.25 inches inner diameter with a 0.375-inch outer diameter and 0.031-inch thickness, engineered to create a watertight seal without restricting fuel flow. The nylon material resists fuel swell and chemical degradation over time, unlike aged cork or composite gaskets that harden and crack under ethanol-blend fuel exposure. The 10-pack quantity allows for multiple rebuilds or provides spares for critical race season prep. Whether you're doing a complete carburetor overhaul or replacing worn needle seats that cause erratic idle and poor throttle response, these washers ensure precise metering and repeatable performance.

Technicians restoring vintage Holley four-barrel carburetors—whether for 427 big-block Chevys, 455 Pontiacs, or 440 Mopars—rely on Advanced Engine Design gasket kits to rebuild fuel bowls and float assemblies correctly. Installation is straightforward: remove the old worn washer, clean the needle seat bore with compressed air, and seat the new nylon washer under the needle assembly. Replace your needle seats at the same interval as ignition points and plugs to maintain consistent cold starts, smooth cruising, and full-throttle response on the street or strip.