CNC-Port-Matched Intake Manifold – Oval-Port, square bore, Holley Carburetors
- Same as P/N 12363406 except it has been CNC-port-matched for GM aluminum oval-port
heads with large oval-port heads (1975-and-older), and all aluminum heads with oval ports

NOTE: Open carburetor spacer is not recommended with use of dual-plane manifolds.