The Cal-Van Tools Three-Valve Ford Triton Insert Kit, No. 39300, is designed to aid in the repair of, three-valve 5.4L and 6.8L engines built before October 9, 2007 and three-valve 4.6 L engines built before November 30, 2007, found in many 2004–2008 Ford, Lincoln and Mercury vehicles. In these models, the spark plug tends to break off in the cylinder head during maintenance. If not repaired properly, this can result in damaged or unusable spark plug threads, or the possibility of a spark plug blow out. This kit will allow the user, with simple step-by-step instructions, to repair those damaged threads or blowouts in 30 minutes or less per cylinder.