Cylinder Head Specifications: Combustion chamber volume: 63cc / 65cc; Intake runner volume: 171cc; Exhaust runner volume: 77cc; Intake valve diameter: 2. 02"; Exhaust valve diameter: 1. 60"; Valve stem diameter: 11/32"; Valve guides: Manganese bronze; Deck thickness: 5/8"; Valve spring diameter: 1. 46"; Valve spring maximum lift: . 575"; Rocker stud: N/A; Guideplate: N/A; Pushrod diameter: 5/16"; Valve angle: 18°; Exhaust port location: Stock; Spark plug fitment: 14mm x 3/4 reach, gasket seat. * The special valve train in the 1970 340 T/A is not compatible with these cylinder heads. Match with Edelbrock head gasket sets. Bare heads will have valve guides & 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 3/4" reach with flat gasket seat. Deck thickness: 5/8", pushrod diameter: 5/16".