Holley Street Avenger Model 4150 570 CFM 4-Barrel Carburetor - Square Bore - Electric Choke - Vacuum Secondary - Dual Inlet - Silver 23-FLT-NFO-M No tune is required

No tune is required

This gasket set replaces the gaskets that came with your 221500 TH400 Valve Body

Gauges feature an 1/8" NPT male fitting

Thread Size 7/8 in

Holley Street Avenger Model 4150 570 CFM 4-Barrel Carburetor - Square Bore - Electric Choke - Vacuum Secondary - Dual Inlet - Silver 23-FLT-NFO-M No tune is requiredHolley Street Avenger Carburetor 0 80570 4 bbl 570 CFM Vacuum Secondary Automatic Choke Over 300 hp Use Carb (0 80670) Adjustable Vacuum Secondary 4th Generation Power Valve Fuel Metering System Built In Secondary Fuel Filters External Float Adjustable w Sight Plug On Vehicle Electric Choke 4 Vacuum Ports Street Ready; Out Of The Box Vehicle Applications: 1969 1974 Chevrolet K30 Pickup 1969 1981 Chevrolet Corvette 1969 1969 Mercury Cougar 1975 1978