These are our very own custom made flow bench developed high flow stainless valves for the 2.3. These flow over 25cfm better than any other brand valve intake and exhaust. The secret is our 7mm necked down stem itake valve with custom back cut angle and tulip shaped exhaust valve.  The exhaust valves are designed for high heat durabilitty with inconel like properties.  11/32 chrome plated stems for long life. 1.89" intake and 1.60" exhuaust head diameters. These are +.050" long to correct geometry in roller cam setups and utilize a .400" tip length for High lift camshafts up to .660" lift.