Fit for SBC BBC 302 350 454 383, fits all 3" collectors with triangle(3 bolt pattern) Description: brand new 3" Copper Header Exhaust Collector Gaskets Fits All 3" Collectors With Triangle (3 Bolt Pattern) Made Of Solid Copper 0.041" Thick No Sealant Required Reusable Seal Perfectly Every Time By Creating A Tight Leak Proof Seal By Using A Clad O-Ring Design That Will Last! Center To Center Bolt Hole Measurement is 3-3/8" Bolts Are Not Included.