2002 mustang PI heads..? Weird stamping on head.
 

The guy said they were patriot ported heads. He sent me a picture of the drivers side head and it had the numbers "06 3" stamped IN the head on the side.. He said this engine is bad. He said he keeps up with his 500 horse lightning. Puts bus lengths on his 98 cobra, and he said for me to some test drive it. What's that stamp mean??? Anyone?