L31 Vortec Small Block Chevrolet Cast Iron Cylinder Head

The Chevrolet Performance 19436449 is an assembled cast iron cylinder head designed for L31 Vortec Small Block Chevrolet engines, offering a significant performance upgrade over earlier cast iron heads. Patterned after the LT1 cylinder heads, these Vortec heads were first utilized on the 1996 fuel-injected pickup truck RP0 Code L31. They come equipped with 1.940" intake valves and 1.500" exhaust valves, complementing a high-velocity port design. The fast-burn combustion chamber contributes to producing substantial horsepower right out of the box. This cylinder head features a 64cc combustion chamber and 170cc intake ports. The included stock valve springs are suitable for camshafts with a maximum lift of up to 0.450". The head can be mildly ported for additional performance gains and can be milled up to .040" to increase the compression ratio. It's important to note that the Vortec head requires a specific Vortec-style intake manifold due to its improved manifold mounting flange, gasket design, and raised intake ports; modification to accept early design intake manifolds is not recommended. Available manifolds include P/N12366573, 12496820, 1249621, and 12496822. Vortec heads are compatible with all small-block Chevrolet engines produced from 1955 to the present, with the exclusion of LT1/LT4 reverse coolant flow engines and current LS1 style engines. The heads are completely assembled with valves, springs, retainers, and 3/8" rocker studs, and require the use of self-aligning rocker arms. For camshafts with lift exceeding .475", modifications to the valve guide bosses may be necessary to prevent crushing valve stem seals. The valve spring seat diameter is 1.48".