Autolite High Thread Pro Spark Plugs are engineered with a unique OE patented design that results in more durability and greater power from a more comprehensive seal improved heat transfer and more focused ignition power. These plugs are OE designed specifically for Ford 3V engines offering four specific heat ranges to match the specific requirements of high performance Ford models; Ford Lincoln and Mercury trucks and Ford Mustangs. Autolite spark plugs are the best alternative to OE spark plugs offering OE form fit and function for all makes and models both foreign and domestic at a value price. Autolite provides the automotive aftermarket and original equipment manufacturers with the highest quality ignition products and is the leading supplier of spark plugs.