{"product_id":"mangum-racing-267cc-ls3-cylinder-heads","title":"Mangum Racing 267cc LS3 Cylinder Heads","description":"\u003cp\u003eThese Mangum Racing 267cc LS3 heads use a 6-bolt casting with increased deck thickness while retaining the OEM 15° valve angle and LS3 valve spacing. A 267cc CNC intake runner and 96cc exhaust port provide strong mid-lift response and stable high-lift flow for serious stock-geometry naturally aspirated and boosted combinations.\u003c\/p\u003e\u003ch3\u003eKey Features\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e6-bolt Mangum Racing LS3 casting with increased deck thickness\u003c\/li\u003e\n\u003cli\u003e15° valve angle with OEM LS3 valve spacing\u003c\/li\u003e\n\u003cli\u003e267cc CNC intake ports, 96cc exhaust ports, and 68.5cc CNC chambers\u003c\/li\u003e\n\u003cli\u003e2.165\" hollow-stem stainless intake valves and 1.600\" hollow-stem stainless exhaust valves\u003c\/li\u003e\n\u003cli\u003eBronze guides, PAC .660\" dual springs, titanium retainers, Viton seals, and 1.250\" steel spring seats\u003c\/li\u003e\n\u003cli\u003eChamber softening available for 4.000\", 4.065\", and 4.125\" bores; minimum bore 4.000\"\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eAirflow Performance\u003c\/h3\u003e\u003cp\u003eSuperFlow data with a 4.125\" bore plate; intake uses a radius entry and exhaust is tested without a pipe.\u003c\/p\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eValve Lift\u003c\/th\u003e\n\u003cth\u003e.200\u003c\/th\u003e\n\u003cth\u003e.300\u003c\/th\u003e\n\u003cth\u003e.400\u003c\/th\u003e\n\u003cth\u003e.500\u003c\/th\u003e\n\u003cth\u003e.600\u003c\/th\u003e\n\u003cth\u003e.700\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eIntake CFM\u003c\/th\u003e\n\u003ctd\u003e148\u003c\/td\u003e\n\u003ctd\u003e227\u003c\/td\u003e\n\u003ctd\u003e282\u003c\/td\u003e\n\u003ctd\u003e325\u003c\/td\u003e\n\u003ctd\u003e350\u003c\/td\u003e\n\u003ctd\u003e363\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eExhaust CFM\u003c\/th\u003e\n\u003ctd\u003e114\u003c\/td\u003e\n\u003ctd\u003e164\u003c\/td\u003e\n\u003ctd\u003e200\u003c\/td\u003e\n\u003ctd\u003e233\u003c\/td\u003e\n\u003ctd\u003e240\u003c\/td\u003e\n\u003ctd\u003e243\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003e\u003cstrong\u003eInstallation note:\u003c\/strong\u003e Verify pushrod length after selecting the camshaft, gasket thickness, and final chamber size.\u003c\/p\u003e","brand":"Mangum Racing","offers":[{"title":"Default Title","offer_id":54111765561663,"sku":"MR-267LS3","price":2099.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0760\/2041\/6831\/files\/mangum-racing-mr-267ls3_a0e7ab69-7bd1-4a67-81e3-7d6be43e20a3.webp?v=1784146844","url":"https:\/\/smgspeed.com\/products\/mangum-racing-267cc-ls3-cylinder-heads","provider":"SMGspeed","version":"1.0","type":"link"}