Proform 67212 Street Series 650 CFM Polished Aluminum Dual Inlet 4-Barrel Square Bore Mechanical Secondary Carburetor with Electric Choke Proform Street Series Carbs are manufactured from light weight aluminum Adjustable idle air bleeds mean easy non-permanent calibration is possible and just at your fingertips No drills necessary with this carburetor Billet throttle body offers outstanding strength and precision throttle shafts promise long term performance