Overview:99-02 Chevy/GMC Sierra/Silverado/Suburban/Yukon/Escalade: 6.0L, Tube Size 1.625" O.D., w/EGR; Black Paint; 50-State Legal header C.A.R.B. EO #D-115-16.Features: This is a 50-State Legal header C.A.R.B. EO #D-115-16. Sturdy 16 gauge tubing Extra thick 3/8” flanges for a leak-free seal Designed as a direct fit replacement for OEM exhaust manifolds Will accommodate all emission control devices Bolts directly to factory head pipe Complete with premium gaskets and hardware Application: 1999-2002 Chevrolet Silverado 2500 1999-2002 GMC Sierra 2500 2000-2002 Chevrolet Suburban 2500 2000-2002 GMC Yukon XL 2500 2001-2002 Chevrolet Silverado 1500 HD 2001-2002 Chevrolet Silverado 2500 HD 2001-2002 Chevrolet Silverado 3500 2001-2002 GMC Sierra 1500 HD 2001-2002 GMC Sierra 2500 HD 2001-2002 GMC Sierra 3500 2002 Cadillac Escalade 2002 Cadillac Escalade EXT Specs: Brand Flowtech C.A.R.B. EO # D-115-16 CARB (California) Compliant Yes CARB EO# D-115-16 Collector Diameter 2.50 inch Emission Code 1 Header Finish Black Paint Header Style Shorty Primary Tube Dia. 1-5/8 inch Product Type Headers Tube Material Mild Steel Warning California Proposition 65