We used the Helicoil Save-A-Thread M14x1.25 to do an "over the fender" repair of the spark plug thread on a 2003 Ford Expedition 5.4L V-8 with a blown spark plug. I thought I might have to buy a Time-Sert kit, but found the Helicoil version at a much lower price. The Helicoil worked very well, even though the plug was way at the back in a difficult spot under the fuel rail. The two step tap design was very easy to use and reamed and cut the larger threads no problem. I had read a few tips that really helped out: 1) load up the flutes in the tap with grease to catch the thread cuttings and also it allows you to see progress if you back out the tap a few times during the process, 2) start the engine up after tapping without the spark plug - it appeared to blowout some very fine aluminum cuttings that weren't caught by the grease and 3) thread the insert on to the sparkplug and then thread the plug into the newly tapped hole. I wasn't concerned about setting the insert, since I figured I wasn't going to be changing the plug again for a long time, and it would be no big problem if the insert came out with the plug. The first set of plugs looked great after 115K miles so I figured I've got another 100K on the new plug. Some people also recommended manually advancing the engine to the point where both valves were closed for that cylinder and also using a vacuum to suck out any shavings, but I thought the grease worked well enough to not bother with the vacuum approach. The ignition coil for that plug had to be replaced because it got broken when the plug blew out, but beyond replacing that, the engine was running great with just a few hours work.