{"product_id":"vortec-cast-iron-cylinder-head-assembly","title":"Vortec Cast Iron Cylinder Head Assembly","description":"The Chevrolet Performance 19436449 is a complete cast iron Vortec cylinder head assembly, serving as a high-performance upgrade for small-block Chevrolet engines. It replaces GM part numbers 12558060 and 12691728, offering a substantial value proposition for power gains.\n\nThey utilize 1.94-inch intake valves and 1.50-inch exhaust valves to complement their port design. Out of the box, the Vortec head flows better than the Bow-tie head and is reported to provide a 20 to 40 horsepower bolt-on increase over earlier cast iron small-block heads.\n\nThese cylinder heads are compatible with all small-block Chevrolet engines produced from 1955 to the present, with specific exclusions for LT1\/LT4 reverse coolant flow engines and current LS1 style engines. It's important to note that the Vortec head requires a Vortec-style intake manifold due to its improved manifold mounting flange and gasket design, as well as its raised intake ports. Modifications to accept early design intake manifolds are not recommended. Compatible manifolds include P\/N 12366573, 12496820, 1249621, and 12496822.\n\nThe assembly comes completely outfitted with valves, springs, retainers, and 3\/8-inch rocker studs. For optimal performance, the use of self-aligning rocker arms is required. The maximum camshaft lift is rated at .475 inches. Additionally, the valve seats can be machined to accommodate 2.02-inch intake and 1.60-inch exhaust valves, and the rocker arm studs can be pinned or drilled and tapped for 3\/8-inch applications. Casting part numbers for these heads are 10239906 or 12558062.","brand":"Chevrolet","offers":[{"title":"Default Title","offer_id":52687366684984,"sku":"19436449","price":795.65,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0970\/4895\/3144\/files\/660684870.jpg?v=1784883310","url":"https:\/\/store.motormia.co\/products\/vortec-cast-iron-cylinder-head-assembly","provider":"MOTORMIA","version":"1.0","type":"link"}