Assembled; LS3 Engines; Aluminum; Angle Plug; 260 CC Intake Port/ Rectangular; 6 Bolt; 69 CC Combustion Chamber; 2.165 Inch Intake Valve Diameter/ 1.600 Inch Exhaust Valve Diameter; 1.270 Inch Outside Spring Diameter; Set Of 2; With Dual Springs/ Retainers/ Valve Seats