The ProMAXX Thread Repair Kit restores stripped or damaged 8mm x 1.25mm threads. Unlike spring-type inserts, which may fail under extreme temperatures; our kit is designed with Black Oxide inserts that are stronger than the threads that they replace. More holding power, extreme heat resistance, resulting in a better solution for damaged threads. This kit is compatible with all of our 200 / 300 series providing the technician with the ability not only to extract a damaged bolt but also restore the threads to factory new condition. While this kit is compatible with our kits, the Thread Repair Kit can also be used by itself. Engineered to fix problems caused by previous repair attempts as well. The kit includes precision high-quality tooling, a ProBushing, ProDrill Gold tooling bits, tap, and four 8 mm x 1.25 inserts. Cylinder head threads used for mounting exhaust manifolds on 4.6L, 5.4L, and 6.8L engines are losing their ability to meet Ford torque specs following a repair. This is due to repetitive Exhaust Manifold Repairs (EMRs) made throughout the lifecycle of the engine. Spring-type inserts are a temporary fix and rely on the integrity of the thread for their holding power. To support our network of EMR clients, ProMAXXÂŽ Tool designed and manufactured solid steel inserts that are stronger than the aluminum heads they restore. These inserts exceed Ford torque specs for the manifold