Is it an NA head or Turbo?
Reply #5 –
Take a magnet to the exhaust valves. The turbo valves, which are made from inconel, won't be magnetic. Dead give away. Just the valve head will be inconel, not the stem. Also another dead give away is that the early carbed turbo's that used an oval intake port head will have the oil drain back in the head, by the #4 spark plug.
That's an N/A head.