{"product_id":"bare-1938-1939-el-knucklehead-cylinder-head-set","title":"Bare 1938-1939 EL Knucklehead Cylinder Head Set","description":"\u003cp\u003e1938-1939 EL bare Knucklehead cylinder head set features exact casting marks and details for 1938 61 inch Knucklehead models.\n\u003cbr\u003eFeatures a small intake port. The valve spring cover is not included. *NOTE: Accepts cup valve cover  primer caps and large 18mm air cooled spark plugs  all items available separately. *NOTE: Accepts large 1-3\/8 inch hex Doering #3 spark plug set. *NOTE: 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. \n\u003cbr\u003e Tech Notes: Suggested to use with #42-3637 Lower Valve Spring Cup Set Parkerized. Suggested to use with #49-0009 Brass Head Primer Cups. Suggested to use with #49-0878 18mm Doering Spark Plug Set. \n\u003cbr\u003e Instructions: http:\/\/www.vtwinmfg.com\/Instructions\/49\/49-1349.pdf\u003c\/p\u003e","brand":"Motortechnic","offers":[{"title":"Default Title","offer_id":67611536687289,"sku":"49-1349","price":10320.99,"currency_code":"USD","in_stock":false}],"url":"https:\/\/www.thespeedshopusa.com\/products\/bare-1938-1939-el-knucklehead-cylinder-head-set","provider":"THE SPEED SHOP USA","version":"1.0","type":"link"}