{"product_id":"prc-225cc-as-cast-cathedral-port-cylinder-heads-ls1-ls2-applications","title":"PRC 225cc As-Cast Cathedral-Port Cylinder Heads — LS1\/LS2 Applications","description":"\u003cp\u003e\u003cstrong\u003ePRC 225cc As-Cast Cathedral-Port Cylinder Heads — LS1\/LS2 Applications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003ePart Number: PRC-SSAsCast225\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003ePrecision Race Components PRC-SSAsCast225 cylinder heads combine high-flow 225cc as-cast cathedral-port intake runners with CNC-machined combustion chambers and valve-guide machining for high-performance LS applications. PRC designed the 225cc casting to support combinations ranging from performance street engines with moderate camshafts through substantially higher-output naturally aspirated and boosted builds.\u003c\/p\u003e\n\u003cp\u003eThe current 62cc version uses a compact CNC-machined chamber to increase compression and improve power potential in appropriately matched combinations. PRC reports more than 320 CFM of intake airflow, while retaining compatibility with factory LS1-style rocker arms and supplying the heads with TSP\/PAC dual valve springs and titanium retainers.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eKey Features\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e225cc as-cast cathedral-port intake runners\u003c\/li\u003e\n\u003cli\u003eCNC-machined 62cc combustion chambers\u003c\/li\u003e\n\u003cli\u003eCNC-machined valve-guide areas\u003c\/li\u003e\n\u003cli\u003ePRC flow-bench tested intake airflow of more than 320 CFM\u003c\/li\u003e\n\u003cli\u003e2.065-inch intake valves\u003c\/li\u003e\n\u003cli\u003e1.600-inch stainless-steel exhaust valves\u003c\/li\u003e\n\u003cli\u003eTSP .660-inch dual valve-spring package with PAC springs\u003c\/li\u003e\n\u003cli\u003eTitanium valve-spring retainers\u003c\/li\u003e\n\u003cli\u003eUses factory LS1-style rocker arms\u003c\/li\u003e\n\u003cli\u003eCast and machined in the USA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eKit Includes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003ePair of fully assembled PRC 225cc as-cast cathedral-port cylinder heads\u003c\/li\u003e\n\u003cli\u003e2.065-inch intake valves\u003c\/li\u003e\n\u003cli\u003e1.600-inch stainless-steel exhaust valves\u003c\/li\u003e\n\u003cli\u003eTSP .660-inch dual valve springs with PAC springs\u003c\/li\u003e\n\u003cli\u003eTitanium retainers\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eTechnical Specifications\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eIntake port configuration: Cathedral port\u003c\/li\u003e\n\u003cli\u003eIntake runner volume: 225cc\u003c\/li\u003e\n\u003cli\u003eCombustion chamber volume: 62cc\u003c\/li\u003e\n\u003cli\u003eCombustion chamber finish: CNC machined\u003c\/li\u003e\n\u003cli\u003eIntake valve diameter: 2.065 in\u003c\/li\u003e\n\u003cli\u003eExhaust valve diameter: 1.600 in\u003c\/li\u003e\n\u003cli\u003eValve-spring configuration: TSP .660-inch dual spring kit with PAC springs\u003c\/li\u003e\n\u003cli\u003eRetainers: Titanium\u003c\/li\u003e\n\u003cli\u003eRocker-arm compatibility: Factory LS1-style rocker arms\u003c\/li\u003e\n\u003cli\u003ePublished peak intake flow: 321 CFM @ .650-inch lift\u003c\/li\u003e\n\u003cli\u003ePublished peak exhaust flow: 230 CFM @ .650-inch lift\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003ePublished Flow Data\u003c\/strong\u003e\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eValve Lift\u003c\/th\u003e\n\u003cth\u003eIntake Flow\u003c\/th\u003e\n\u003cth\u003eExhaust Flow\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e.100 in\u003c\/td\u003e\n\u003ctd\u003e68 CFM\u003c\/td\u003e\n\u003ctd\u003e56 CFM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e.200 in\u003c\/td\u003e\n\u003ctd\u003e145 CFM\u003c\/td\u003e\n\u003ctd\u003e113 CFM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e.300 in\u003c\/td\u003e\n\u003ctd\u003e210 CFM\u003c\/td\u003e\n\u003ctd\u003e164 CFM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e.400 in\u003c\/td\u003e\n\u003ctd\u003e257 CFM\u003c\/td\u003e\n\u003ctd\u003e200 CFM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e.500 in\u003c\/td\u003e\n\u003ctd\u003e300 CFM\u003c\/td\u003e\n\u003ctd\u003e214 CFM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e.600 in\u003c\/td\u003e\n\u003ctd\u003e318 CFM\u003c\/td\u003e\n\u003ctd\u003e229 CFM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e.650 in\u003c\/td\u003e\n\u003ctd\u003e321 CFM\u003c\/td\u003e\n\u003ctd\u003e230 CFM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003e\u003cstrong\u003eApplication Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eDesigned for cathedral-port LS applications and marketed by PRC\/Texas Speed for LS1\/LS2 combinations.\u003c\/li\u003e\n\u003cli\u003eTexas Speed currently recommends the 225cc head family primarily for 5.7L, 6.0L, and larger cathedral-port LS combinations.\u003c\/li\u003e\n\u003cli\u003eThe current 225cc head\/cam package documentation specifies a minimum 3.903-inch cylinder bore for clearance with the 2.065-inch intake valve. Verify bore diameter and valve-to-cylinder clearance for the specific short block before final assembly.\u003c\/li\u003e\n\u003cli\u003eThe 62cc chamber is intended to increase compression relative to larger-chamber combinations. Final compression ratio depends on displacement, piston configuration, deck height, head-gasket dimensions, and chamber volume.\u003c\/li\u003e\n\u003cli\u003ePRC also offers a separate 68cc big-chamber version under a different part number. PRC-SSAsCast225 is the 62cc configuration and should be cataloged separately rather than as a chamber-size variant.\u003c\/li\u003e\n\u003cli\u003ePushrod length, piston-to-valve clearance, and valvetrain geometry should be verified for the complete engine combination.\u003c\/li\u003e\n\u003cli\u003eHead gaskets, head bolts or studs, rocker arms, pushrods, intake manifold, exhaust components, and installation gaskets\/hardware are not listed as included with this cylinder-head set.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eEmissions and Competition-Use Notice\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cem\u003eThis product is not legal for sale or use in the state of California. Installation or use on an emissions-controlled vehicle may also be restricted by federal, state, or local law. The purchaser and installer are responsible for confirming that the completed vehicle and application comply with all applicable emissions and vehicle-use requirements.\u003c\/em\u003e\u003c\/p\u003e","brand":"Precision Race Components (PCR)","offers":[{"title":"Default Title","offer_id":46292124205113,"sku":null,"price":2499.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0809\/8512\/9017\/files\/3515_1_1_c323625d-032f-468c-ae17-3a7053246b29.webp?v=1786309906","url":"https:\/\/rad-power.com\/products\/prc-225cc-as-cast-cathedral-port-cylinder-heads-ls1-ls2-applications","provider":"RAD","version":"1.0","type":"link"}