Black Diamond 1,575"/40mm T=23 Steam Diameter 0,2805" The valve guides must be reamed/honed to set the correct clearance, and then a valve job should be performed to insure proper valve sealing.
Race profile. New cams must be hardwelded. Requires Exhaust System, High Compression Piston, Shortened Valve Guides, and Performance Valve Spring Kit. Check ALL clearances!