antivenom

I bought my 1999 GT last year and today I went to change the spark plugs and when I got to #4 I found that it had an autolite revolution HT1 in it but none of the other 7 did? I'm confused because I have never seen a spark plug like this one because its really long and actually screws into what looks like a anti-fowler? Do you guys think that the last owner might have stripped out that cylinder and this was some type of a thread fixer? When I looked up autolite HT1 on the internet it brought me up to a lot of mustang sites and said that they were for 2005-2011 stangs. Let me know if you guys have any ideas. Thanks

cliffyk

I think you may have "hit it on the head", sort of--what you describe could be a poorly installed Time-Sert, with the longer plug used to make up for the botched install???