{"product_id":"1937-1938-el-knucklehead-bare-cylinder-head-set","title":"1937-1938 EL Knucklehead Bare Cylinder Head Set","description":"\u003cp\u003e1937-1938 EL bare Knucklehead head set features OEM production numbers  mc hallmark  small intake port  primer black plugs  manifold nipples and are painted with black heat paint.\u003c\/p\u003e\n\u003cp\u003eExact for 1937 only  but can be used on 1937-1939 61 inch EL models. Either type of valve spring cover can be installed  either cup type of full cover and top set. Accepts  inchBaby Butt inch intake manifold  springs  valves  collars  spring cups and top tins included and assembled. *NOTE: Valve seats are installed but not cut. Uses 1-3\/8 inch large hex 18mm plugs. *NOTE: Heads include feature detailed casting hallmarks  as original  black painted. *NOTE: Accepts large 1-3\/8 inch hex Doering #3 spark plug set. Material of valve seats features a better hardenability and heat resistance than 1.2713. Material is tough with high compressive strength and high tempering resistance. Hardness equals 370-415 HB. Tensile strength equals 1250-1400 N\/mn2. Condition is tempered.\u003c\/p\u003e\n\u003ch3\u003eProduct Details\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e Motortechnic\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eV-Twin Part Number:\u003c\/strong\u003e 49-1310\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Engine\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Group:\u003c\/strong\u003e Cylinder Head\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Assembled\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCountry of Origin:\u003c\/strong\u003e TAIWAN\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFitment\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1937-1938 EL\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003ePlease verify fitment before ordering.\u003c\/em\u003e\u003c\/p\u003e","brand":"Motortechnic","offers":[{"title":"Default Title","offer_id":47498088841300,"sku":"49-1310","price":4575.89,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0700\/0122\/9908\/files\/49-1310a.jpg?v=1786567858","url":"https:\/\/skywaycyclesupply.com\/products\/1937-1938-el-knucklehead-bare-cylinder-head-set","provider":"Skyway Cycle Supply","version":"1.0","type":"link"}