Brand: Allstar Performance Manufacturer's Part Number: ALL25972 Part Type: Carburetor Spacers Product Line: Allstar Performance Carburetor Shear Plates Automotive Fittings Part Number: AAF-ALL25972 UPC: 848238056358 Carburetor Spacer Style: 4-hole Thickness (in.): 0.500 Carburetor Spacer Material: Aluminum Carburetor Spacer Color: Clearcoat Gaskets Included: No Mounting Hardware Included: No Quantity: Sold individually. Notes: Bore diameter is 2 in. Description: Allstar Performance carburetor shear plates will maximize the performance of your race engine. These carburetor plates with a built-in shear design create a dam under the throttle plates, helping to build low pressure while improving vacuum signal to your carburetor. They are machined from 6061-T6 aluminum and clear anodized to protect against corrosion. If your race engine has a large amount of cam overlap, install carburetor shear plates from Allstar to get the most performance for your setup.