Had a Ford Escape come in today with a plug blown out of a rear cylinder. We sold the costumer re sleeving all six cylinders. Fords are tricky because the plugs have no collar, using a conventional heli-coil/timecert won’t work. If you try that route the new tapped hole has a larger diameter then the plug, and it’ll just keep screwing in until it falls into the engine. The only repair is a “top hat” insert like the one in the pic. The kit I have is specially for the Triton series of engines. The guide for the reamer and tap won’t work for this application so I had to do all six free hand, 🤦♂️. Having a borescope, such as the Snapon bk3000 allows you to preform this job much easier, and allows you to insure your work is sound. First you set the cylinder to top dead center on the compression stroke. This is necessary to get all the metal shavings out of the engine. Next you drill out the old threads. The kit I use actually has a reamer and it works very well. I use a vacuum to get as much metal out as I can, the use shop air for the rest. Next you tap out the hole, making sure you tap completely through the hole, but don’t allow the tap to fall through the hole. I repeat the same steps to remove all the turnings from the engine, and use the bore scope to inspect and make sure it’s all out. Finally I epoxy the insert threads and use the plug to install the insert. This job isn’t cheap, I charge RR plug labor plus 1.0 per hole. It is however much cheaper then replacing the cylinder heads. My experience is that when one fails the others aren’t far behind, so I encourage getting them done all at once.