HDR CRMC 66-74 CHVY/GMC TRK Flowtech headers are the perfect combination of performance and value. Flowtech long tube headers are precision engineered using mandrel bent tubing, formed collectors and 5/16" flanges with sealing rings for a leak-free seal. All mounting hardware and gaskets are included for a simple installation. This header is coated in a high heat and corrosion resistant metallic ceramic thermal coating that increases exhaust velocity and reduces underhood temps for increased performance. Features: Fuel Economy From The Engine Leak Test For Max Performance Ceramic Headers Rust And Corrosion Resistance Mandrel-Formed Power Plenum Leakproof O-Ringed Port Seals Include All Mounting Hardware Works with power steering and power brakes Application 1969 - 1974 Chevrolet Blazer 1966 - 1974 Chevrolet C10 Pickup 1973 - 1974 Chevrolet C10 Suburban 1966 - 1974 Chevrolet C20 Pickup 1973 - 1974 Chevrolet C20 Suburban 1966 - 1974 Chevrolet C30 Pickup 1966 - 1974 Chevrolet K10 Pickup 1973 - 1974 Chevrolet K10 Suburban 1966 - 1974 Chevrolet K20 Pickup 1973 - 1974 Chevrolet K20 Suburban 1968 - 1974 Chevrolet K30 Pickup 1966 Chevrolet Suburban 1967 - 1974 GMC C1500 Pickup 1973 - 1974 GMC C1500 Suburban 1967 - 1974 GMC C2500 Pickup 1973 - 1974 GMC C2500 Suburban 1967 - 1974 GMC C3500 Pickup 1970 - 1974 GMC Jimmy 1967 - 1974 GMC K1500 Pickup 1973 - 1974 GMC K1500 Suburban 1967 - 1974 GMC K2500 Pickup 1973 - 1974 GMC K2500 Suburban 1968 - 1974 GMC K3500 Pickup Specs Brand Flowtech Collector Diameter 3.00 inch Emission Code 4 Engine Chevrolet Small Block Header Finish Silver Ceramic Header Flange Thickness (in) 5/16 inch Header Style Long Tube Primary Tube Dia. 1-1/2 inch Product Type Headers Tube Material Mild Steel Part Number 31500FLT