Cylinder Head Specifications: Combustion chamber volume:  60cc / 70cc; Intake runner volume:  210cc; Intake runner volume:  210cc; Exhaust runner volume:  75cc; Intake valve diameter:  2. 05"; Intake valve diameter:  2. 05"; Exhaust valve diameter:  1. 60"; Valve stem diameter:  11/32"; Valve guides:  Manganese bronze; Deck thickness:  5/8"; Valve spring diameter:  1. 55; Valve spring maximum lift:  . 650" flat; . 670" roller (A); Rocker stud:  7/16"; Guideplate:  Hardened steel; Pushrod diameter:  5/16"; Valve angle:  20°; Exhaust port location:  Raised . 130"; Spark plug fitment:  14mm x 3/4 reach, gasket seat. INSTALLATION NOTE: Check cam manufacturer's specs for compatibility with valve springs. Recommended valve sizes listed. Match with Edelbrock head gasket sets. Use Head Bolt Kits for easy installation. These heads require the use of a 14mm x 3/4" reach, flat gasket spark plug with a heat range appropriate to your application. Deck thickness: 5/8", rocker stud diameter: 7/16", pushrod diameter: 5/16" (width of slot in guide plate).