The factory exhaust manifold to cylinder head bolts installed in 1999-07 GM 4.8, 5.3 and 6.0 liter V8 engines are known for their excessive corrosion and premature failure (relative to the age and mileage of the vehicle). If not repaired, the problems can develop into exhaust leaks, warped exhaust manifolds and possible failed emissions testing. These replacement bolts are made from higher strength alloys and offer improved corrosion resistance over the original hardware.