Fits for LS Cathedral Port Cylinder Head to Rectangle Port Intake Manifold Adapters 66339204OE Number 551316 LSA LSX Manifold LS3 Will fit Following Models Features and Specifications Can ONLY be used with Cathedral Port Cylinder Heads Compatible with: ANY Cathedral Port Heads and will adapt to ANY rectangle port intakes, supercharger or blower. Will not fit raised port LS7 intakes Package Includes: 2 adapter plates (1 2" thick), orings, 70mm bolts with sealing washers for use with an LSA supercharger Intake manifold bolt lengths required