Description Replaces Stripped Spark Plug Threads On Ford V10, 4.6 And 5.4 Liter Engines. This precision tool accurately replaces stripped Ford spark plug threads with new thread inserts. Works on the car without removing the engine head. This set includes a drill, tap, swedge tool, insert tool, 10 steel inserts, plus a vacuum adapter to remove shavings from the chamber. The tool set installs a new spark plug thread insert in the exact original position in approximately 20 minutes. IMPORTANT: An inspection scope must be used to insure all shavings are removed from the combustion chamber. An inspection scope is not included in the LIS-65900 set. Order a LIS-66090 scope and LIS-66100 45