Pick up this Holley replacement primary metering block for Holley R80783, R80783-1 650 CFM Vacuum Secondary Carburetors and R4777-2, R-4777-3 and R-4777-4 650 CFM Double Pumper Carburetors. Designed to be an exact replacement for your existing carburetor, so no modifications necessary to install them correctly. Manufactured from quality die-cast zinc, a Holley replacement metering block will keep your carburetor running correctly
