my friend had PI heads put on his 96 4.6 motor. the mechanic that did the work didnt time the driver's side head correctly and the valves came ito contact with all the pistons the worst being the 2 in the pics. the new shop that he took it to said that they feel that there is a 90-95% chance that everythting will be ok. Ive seen many pics on the net where this has happened and the people have just knocked down the burr's, replaced valve stems and retimed everything. The motors ran fine. Im looking for advice for my friend. for some unknown reason this is the biggest pic i can post.