Feature: 1. 1in open center style carb spacer, for Holley 4150 carburetor, replacement for Chevy Small/Big Block, replacement for Ford, replacement for Chrysler Mopar engine. 2. Fits 4 barrel carbs with a square bore base like for Holley 4150/4160, for Barry Grant, for Carter and for Edelbrock. 3. Carb spacers extend the length of the intake mixture column and improves the air/fuel distribution. Phenolic plastic style carb spacer also insulates your carb from excessive engine heat. 4. As a general rule, the open design interval increases plenum volume to improve high RPM power, while the 4‑hole design increasesmixture velocity for improved low‑speed and mid‑range torque. 5. Lowering the fuel temperature inside the carburetor results in a denser, more powerful fuel charge to the manifold. Specification: Item Type: Carburetor Spacer Material: Phenolic PlasticSize: Approx. 1in/2.5cmFitment:Fits 4 barrel carbs with a square bore base like for Holley 4150/4160, for Barry Grant, for Carter and for Edelbrock Replacement for Chevy Small/Big Block Replacement for Ford Replacement for Chrysler Mopar engine. Package List: 3 x Carburetor Spacer 4 x Bolt 4 x Nut 4 x Gasket