Full-Torque spark plug thread repair

Lock-N-Stitch Inc. developed the Full-Torque spark plug thread repair, an insert that could produce maximum heat transfer from the spark plug to prevent pre-ignition while providing maximum thread strength. Approved by Ford Motor Co. for use on Triton engines, the easy-to-use probe works by pushing it down into the plug well, pulling it out and reading the Type on the chart engraved on the tool.