1966 GMC PB15 Series Engine: 4.1L L6; 1 Bore Gasket; Position: Carburetor To Intake Manifold;. 1966 GMC PB15 Series Engine: 4.8L L6; 1 Bore Gasket; Position: Carburetor To Intake Manifold;. 1966 GMC PB15 Series Engine: 4.8L L6; 4 -Notch Bypass; 1 Bore Gasket; Position: Carburetor To Governor;.
