Cylinder Head Specifications: Combustion chamber volume: 72cc / 76cc; Intake runner volume: 170cc; Exhaust runner volume: 125cc; Intake valve diameter: 2. 09"; Exhaust valve diameter: 1. 66"; Valve stem diameter: 3/8"; Valve guides: Manganese bronze; Deck thickness: 5/8"; Valve spring diameter: 1. 55"; Valve spring maximum lift: . 600"; Pushrod diameter: 3/8"; Valve angle: 13°; Exhaust port location: Stock; Spark plug fitment: 14mm x 3/4 reach, gasket seat. INSTALLATION NOTE: Match with Edelbrock head gasket sets. 76cc heads have vertical bolt pattern only, 390 GT exhaust will not fit. 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 3/4" reach with flat gasket seat. Deck thickness: 5/8". IMPORTANT NOTES: Direct bolt-on heads for 1961-76 390-427-428 Fords. 428 Cobra Jet-sized valves promote excellent flow for street able power. #60089 can be machined to accept 2. 19" intake and 1. 73" exhaust valves. Rocker shaft stud kit #6009 provides better rocker shaft retention and is highly recommended for use with Edelbrock FE heads. It eliminates wearing of the threads and the possibility of bottoming the rocker shaft bolts in the head. Intake and exhaust CC values are projected if using Edelbrock valves, and equivalent valve job and bowl blend. Edelbrock FE heads do not have the bolt pattern to accommodate the stock GT 390 exhaust manifolds. 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. Replacement valve part numbers are for sets of 8. Deck thickness, 5/8". #6009 rocker shaft stud kit recommended.