Standard Main Jet, 1/4-32 Thread. 057" Jet size. All Holley Main jets are flow tested and then stamped with the correct number. NOT FOR USE WITH CARBURETORS ORIGINALY DESIGNED FOR ALCOHOL.
HOLLEY CARBURETOR STANDARD MAIN JETS HLY122-66 PAIR .066" JET HOLE SIZE AED RACE
HOLLEY CARBURETOR STANDARD MAIN JETS HLY#122-69 PAIR .0693" JET HOLE SIZE RACE
HOLLEY CARBURETOR STANDARD MAIN JETS HLY#122-75 PAIR .082" JET HOLE SIZE RACE
HOLLEY CARBURETOR STANDARD MAIN JETS HLY122-64 PAIR .064" JET HOLE SIZE AED RACE
HOLLEY CARBURETOR STANDARD MAIN JETS HLY#122-71 PAIR .075" JET HOLE SIZE RACE
HOLLEY CARBURETOR STANDARD MAIN JETS HLY#122-74 PAIR .080" JET HOLE SIZE RACE
