Base Plate Insert 1.400 4pk for 1/2in Spacer

The Base Plate Insert 1.400 4pk for 1/2in Spacer from ALLSTAR PERFORMANCE is a precision restrictor plate component engineered for motorsports applications requiring flow control and engine regulation compliance. Available for sale as a four-piece set, these aluminum inserts function as critical fuel system or air restriction components in racing and high-performance engine builds. This product is essential for competitors, engine builders, and fabricators who need reliable restrictor plates to meet sanctioning body specifications or optimize performance parameters.

Manufactured from durable aluminum in a natural finish, the Base Plate Insert 1.400 features a 1.400-inch inner diameter (ID) designed to work with 1/2-inch spacer systems commonly found in carbureted and fuel-injected engines. The aluminum construction provides a lightweight yet rigid solution that resists corrosion while maintaining dimensional accuracy under thermal cycling. Each insert in this four-pack is precision-machined to exact tolerances, ensuring consistent flow restriction and reproducible performance across multiple engines or backup components for critical race applications.

Engine builders and motorsports professionals benefit most from this restrictor plate insert set when standardizing fuel delivery, complying with racing rules, or establishing baseline performance before tuning adjustments. The 1/2-inch spacer compatibility makes these inserts suitable for a wide range of carburetor and fuel rail configurations across street, strip, and track engines. Installation is straightforward—simply position the insert within the spacer assembly, ensuring proper seating and alignment before final torque specifications are applied. For those running multiple vehicles or maintaining spare components for competition reliability, the four-piece configuration delivers value and redundancy.