1974 Porsche 911 RSR 3.0 Liter Twin Plug Factory Racing Heads. Casting Number: 911.104.322.0R - K1819q - Date Codes: Five heads have matching Date Code 8/73 while one shows 1/73.
As a reminder, 'head #2' will have to be sent back to the machine shop to have the conbustion chamber 'champhere' to match the others http://www.pbase.com/9146gt/image/100597909
This MUST be corrected before building the engine. Thanks again Bernie!