Jet Extension 5/16in-32

The MOROSO Jet Extension 5/16in-32 is a precision screw-in jet extension designed for high-performance carburetor tuning in Holley fuel systems. This brass jet extension pair allows fine-tuning of fuel delivery by extending the jet position within the carburetor bowl, a critical adjustment for optimizing air-fuel ratio across varying engine loads and conditions. Built from brass for corrosion resistance and thread reliability, these extensions are essential components for serious carb tuning and performance engine builds.

The 5/16-32 thread specification matches Holley's standard jet bore, ensuring direct compatibility with legacy and modern Holley carburetors. Each extension is manufactured to tight tolerances to maintain consistent fuel flow characteristics and prevent lean or rich running conditions that can damage engines or reduce power output. Brass construction resists fuel degradation and provides reliable seating in carburetor bodies, while the screw-in design allows quick removal for jetting adjustments without disassembling the entire carburetor.

This product is ideal for engine builders, carburetor technicians, hot rod builders, and performance enthusiasts who require precise fuel metering control. Whether dialing in a street engine, race fuel system, or vintage carbureted platform, jet extensions allow critical mid-stream adjustments to fuel delivery without replacing expensive jet sets. The pair quantity supports primary and secondary circuits or provides a spare for experimentation during tuning sessions.

MOROSO is a recognized manufacturer of carburetor components and fuel system accessories, and this jet extension reflects decades of hot rodding and performance carburetor development. Proper jetting remains one of the most impactful tuning variables in carbureted engine performance, and quality extensions ensure that your tuning adjustments deliver repeatable, stable results across throttle positions and engine operating ranges.