Base Plate Insert 1.150 4pk for 1/2in Spacer

The ALLSTAR PERFORMANCE Base Plate Insert 1.150 4pk for 1/2in Spacer (ALL26184) is a precision aluminum restrictor plate insert designed for high-performance racing applications. This four-pack set features a 1.150-inch internal diameter and integrates with 1/2-inch spacer systems commonly found in competition engine builds, carburetor setups, and fuel regulation systems. Each insert is machined from aluminum in natural finish, providing consistent flow characteristics and compatibility with standardized restrictor plate mounting configurations used across bracket racing, circle track, and street performance engines.

The 1.150-inch bore diameter defines the maximum fuel and air flow permitted under rule-restricted competition classes, making bore tolerance critical for compliance and consistent performance across multiple qualifying runs and race events. Aluminum construction balances durability with minimal weight penalty, and the natural finish resists corrosion while allowing straightforward inspection for debris or damage. The four-pack quantity enables racers to maintain matched sets across different carburetors or backup configurations, ensuring uniform intake restriction across their racing program. At 0.21 lbs total weight for the set, these inserts add negligible mass to engine bay components while meeting strict specifications for class legality and flow control.

This product serves bracket racers, circle track competitors, and performance engine builders who must maintain precise fuel and air metering under class rules. Restrictor plate inserts are essential for engines competing in fuel-restricted categories where intake diameter directly controls power output and fuel consumption. Racers upgrading carburetors, rebuilding after wear, or standardizing equipment across multiple vehicles benefit from having a spare set of matched inserts. ALLSTAR PERFORMANCE's reputation in racing components ensures these inserts meet the dimensional accuracy required for legal competition entry and reliable performance lap after lap.