Chev 350 Small Block Remflex Exhaust Manifold Gasket Set D Port Rails # REM2022Chev 350 Small Block Remflex Exhaust Manifold Gasket Set D Port Rails # REM2022 Chev 350 Small Block Remflex Exhaust Manifold Gasket Set D Port Rails 1992 1997 1 7 16 inch width x 1 3 8 inch height RAISED D Shaped Port; Chevy V8 4. 3L LT1 ('94 '96), 5. 7L LT1 ('92 '97), LT4 ('96), Raised D Port, For Headers, 2 Set Use for "Fast Burn Heads" and ZZ4 Crate Motor Port configuration comparable to Fel Pro 1470 Heating and cooling of the exhaust system