THIS COMES WITH 22MM EXHAUST AND 25MM INTAKE VALVES INSTALLED SEE THE ITEM LIST TO THE LEFT ON THIS PAGE. THIS HEAD CAN WORK ON ALL ATC70'S TRX70'S BUT IT WILL HAVE SLIGHTLY LESS COMPRESSION DUE TO THE LARGER DOME (STOCK COMP ON 1973 AND 74 ATC70'S) WORKS FINE ON THE C70K1 AND C70M OT/BH/W/VALVE (S1425) BOTTOM VIEW WITH VALVES INSTALLED ANOTHER SHOT OF THIS HEAD WITH OUT THE VALVES ANOTHER SHOT OF THIS HEAD WITH OUT THE VALVES ANOTHER SHOT OF THIS HEAD WITH OUT THE VALVES ANOTHER SHOT OF THIS HEAD WITH OUT THE VALVES