Holley Standard Main Jets . Size 64 # HO122-64 Rate_Engine while the stock profile versions

while the stock profile versions clear accessories like air-conditioning and alternator brackets

Mounts GM Type II Power Steering pump low on driver side and puts a Sanden Peanut style AC Compressor up on the passenger side

1955-1957 Chevy: 265-400

Square bore

Holley Standard Main Jets . Size 64 # HO122-64 Rate_Engine while the stock profile versionsHolley Standard Main Jets . Size 64 # HO122 64 GENUINE HOLLEY STANDARD MAIN JETS. SALE IS FOR A PACKET OF 2 JETS. Fine tune your carburetor for street or race conditions. These Holley standard main jets are just what you need to fine tune your carburetor for street or race. Threaded for easy installation and removal, Holley jets are manufactured to high tolerances for consistency.