Cylinder Head Specifications: Combustion chamber volume:-?75cc, Intake runner, volume:-?310cc, Exhaust runner volume:-?100cc, Intake valve diameter:-?2.19in, Exhaust valve diameter:-?1.76in, Valve stem diameter:-?11/32in, Valve guides:-?Manganese bronze, Deck thickness:-?5/8in, Valve spring diameter:-?1.55in, Valve spring maximum lift:-?.700in, Rocker stud:-?7/16in, Guideplate:-?Hardended steel, Pushrod diameter:-?3/8in, Exhaust port location:-?Stock, Spark plug fitment:-?14mm x 3/4 reach, gasket seat. INSTALLATION NOTE: Match with Edelbrock head gasket sets. Bare heads will have valve guides and seats installed, but will require final sizing and a valve job to match the valves you will be using. Recommended spark plugs are Champion RC12YC or equivalent 14mm x 3/4in reach with flat gasket seat. Deck thickness: 5/8in, rocker stud diameter: 7/16in, pushrod diameter: 3/8in (width of slot in guide plate). Bare heads will have valve guides and seats installed, but will require final sizing and a valve job to match the valves you will be using. Deck thickness: 5/8in, rocker stud diameter: 7/16in, pushrod diameter: 3/8in (width of slot in guide plate).