Edelbrock . 60869

1987-1991 Corvette (Centerbolt Valve Covers)Port Volumes: 165cc/65cc60cc Combustion ChamberBare Head, Sold Individually Designed for 1986-91 Tuned Port Injected (T.P.I) 5.7L small-block Chevy Corvette engines originally equipped with centerbolt valve covers. Performer centerbolt cylinder heads are 50-state street legal and accept factory centerbolt valve covers. The intake bolt pattern utilizes the 1986-91 (straight) 90&deg; angle on all bolts. Spark plugs are angled like stock O.E. heads. <br><Br>Combustion Chamber Volume:60ccIntake Runner Volume:165ccExhaust Runner Volume:65ccIntake Valve Diameter:2.02''Exhaust Valve Diameter:1.60''Valve Stem Diameter:11/32''Valve Guides:Manganese BronzeDeck Thickness:5/8''Valve Spring Diameter:1.46''Valve Spring Maximum Lift:0.575''Rocker Stud:3/8''Guideplate:Hardened SteelPushrod Diameter:5/16''Valve Angle:23&deg;Exhaust Port Location:StockSpark Plug Fitment:14mm x 3/4'' Reach, <br>Gasket Seat<br><br>Valve LiftIntakeExhaust.100''6454.200''12296.300''177124.400''217147.500''229166.600''232175.700''N/AN/AFlow Numbers as tested by Edelbrock's SuperFlo SF-1020 flow bench @ 28'' H2O<br><Br>Technical Notes: 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...