Stainless Steel Performance Exhaust Headers For Small Block SBC Chevy/Pontiac/Buick Cars Only, 265-400 Ci V8 Fit: Chevy Small Block SBC 265-400Ci GEN I V8. Cars Only! Car Models: Chevy/Pontiac/Buick Camaro, Caprice, Cutlass, Firebird, Lemans, Malibu, Monte Carlo, and Regal Tube Diameter: 1.75". Collector Size: 2.85". Flanged Connection Gasket(s), Bolt(s) Are Included As Pictured TIG Weld & Mandrel-Bent For Maximum Performance