Main Stud girdles provide 30-35% more strength to the bottom end of your engine and they actually prevent main cap flex and main cap walk. Add a windage tray and you immediately improve horsepower. They effectively create a torque box effect on your engine and are constructed out of .39" Chromoly steel for superior strength. All kits feature high grade main cap bolts for reliable quality strength. they also help improve horsepower by acting like a crank scraper