{"product_id":"mangum-racing-cnc-ported-243-799-cylinder-heads-pair-assembled-no-core","title":"Mangum Racing CNC Ported 243\/799 Cylinder Heads PAIR - Assembled - NO CORE","description":"\u003cp\u003e\u003cstrong\u003eMangum Racing CNC Ported 243\/799 Cylinder Heads PAIR - Assembled - NO CORE\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003eChoose your stage!\u003c\/p\u003e\n\u003cdiv\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003eThe Mangum Racing Ported 243\/799 LS6 Cylinder Heads are designed to transform proven GM factory castings into a reliable, high-performance upgrade. Starting with carefully selected seasoned cores, each set features CNC ported runners and a precision valve job for consistent airflow and long-term durability.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eKey Features\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eCNC ported intake and exhaust runners\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003ePrecision CNC valve job\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eFully assembled and ready to run\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003ePAC Racing dual valve springs with titanium retainers\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eStock GM valves (stage 1) Stainless Steel 2.02\/1.57 Valves (Stage 2.5)\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eHand-finished and assembled in-house\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cbr\u003e\u003cstrong\u003eAirflow Performance Stage 1\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003eIntake: .200” – 145 CFM | .300” – 206 CFM | .400” – 256 CFM | .500” – 293 CFM | .600” – 309 CFM | .650” – 311 CFM\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003eExhaust: .200” – 117 CFM | .300” – 155 CFM | .400” – 195 CFM | .500” – 212 CFM | .600” – 228 CFM | .650” – 230 CFM\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eAirflow Performance Stage 2.5\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003eIntake: .200” – 145 CFM | .300” – 208 CFM | .400” – 258 CFM | .500” – 296 CFM | .600” – 3010 CFM | .650” – 312 CFM\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003eExhaust: .200” – 118 CFM | .300” – 157 CFM | .400” – 199 CFM | .500” – 216 CFM | .600” – 232 CFM | .650” – 238 CFM\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003cstrong\u003eConstruction Details\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eSeasoned GM 243\/799 castings\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e228cc CNC intake ports\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e62.5cc CNC combustion chambers\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e2.00” intake \/ 1.55” exhaust valves (stage 1) 2.002” intake \/ 1.57” exhaust stainless valves (Stage 2.5)\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003ePAC dual spring package\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e15° valve angle with factory guides\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cbr\u003e\u003cstrong\u003eFitment\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eMinimum bore: 3.780”\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eCompatible with 4.8L, 5.3L, 5.7L, 6.0L LS engines and larger\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cbr\u003eIdeal for camshaft upgrades, class racing applications, or improving reliability on LS engines, these heads offer proven performance while retaining factory-style castings.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Mangum Racing","offers":[{"title":"Stage 1","offer_id":46628682891462,"sku":null,"price":1499.99,"currency_code":"USD","in_stock":true},{"title":"Stage 2.5","offer_id":46628682924230,"sku":null,"price":1649.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2716\/4086\/files\/243mangum.png?v=1785266651","url":"https:\/\/www.glennsautoperformance.com\/products\/mangum-racing-cnc-ported-243-799-cylinder-heads-pair-assembled-no-core","provider":"Glenn's Auto Performance","version":"1.0","type":"link"}