[bingo2]

Ford had this problem on the 5.4L V8 from 97 to about 2001; then revised the design of the cylinder head adding additional metal and therefore threads to the spark plug hole.

The 4.6L issue wasn't blow out, it was carbon forming on the tip of the two piece plug and making removal very difficult, usually resulting in a broken insulator. Ford redesigned the 4.6L heads in mid 2008 and went to a smaller diameter one piect plug wto solve the problem.