{"product_id":"stealth-aluminum-cnc-cylinder-head","title":"Stealth Aluminum CNC Cylinder Head","description":"The 440 Source Stealth Aluminum CNC Cylinder Head offers significant performance enhancements through advanced manufacturing. These heads are fully CNC machined on both the intake and exhaust ports, increasing the intake port volume from a stock 212cc to 255cc. This precise, computer-controlled machining process ensures that all ports are identical in shape and volume, leading to consistent and accurate flow numbers for every port on every head.\n\nThe enlarged intake ports are capable of flowing over 320 CFM, which can contribute to high horsepower ranges, reportedly in the high 600s to low 700s for an average stroker motor. The product is sold as a single head assembly; an order quantity of two is required for a pair.\n\nFor installation, these heads utilize a 3\/4\" reach spark plug, a standard size found in many small block and Hemi engines. When installing, a thorough inspection and mockup are recommended to check for pushrod clearance. While typically not an issue with factory 5\/16\" pushrods, larger performance pushrods may require some slight clearancing of the pushrod channels. The mockup is also an ideal time to verify rocker geometry, pushrod length, and piston-to-valve clearance. Any necessary clearancing can be performed with a die grinder or Dremel tool.\n\nRegarding compatibility, the combustion chambers were redesigned in mid-2009 to an 80cc size, ensuring they can be used with any head gasket on the market without overhang issues. The product also requires specific head bolts with a reduced diameter 12-point head due to a countersunk bolt seating area and hardened washers to protect the aluminum surface. All necessary hardware, including locks, retainers, and seals, is included with the double spring versions.","brand":"440 Source","offers":[{"title":"Default Title","offer_id":52686707294520,"sku":"200-1080","price":999.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0970\/4895\/3144\/files\/660670687.jpg?v=1784876080","url":"https:\/\/store.motormia.co\/products\/stealth-aluminum-cnc-cylinder-head","provider":"MOTORMIA","version":"1.0","type":"link"}