Well I got the head off tonight and the results are 1 exhaust valve has a chunk out of it . The piece of spark plug got under the valve and cut a notch in the valve then the blow torch effect set in . No damage to the seat or piston or cylinder head . I wish I would have found this site sooner . Now to get the Bosch plugs out of the Alfa . Do you service technicians recommend replacing all of the head bolts , the manual says to just check for stretch 120,000 miles on the car .