Featuring Specially Designed 1 /2 Inch Shank And 7/16 Inch Th read Diameters, These Arp Ring Gear Bolts Were Designed To S urvive In The Toughest Nascar Competition. Installing An Arp Ring Gear Bolt Kit Assures Yo u The Utmost Reliability, Even With The Stresses Of Today's High Horsepower Engines And Hi gh Tech Compounds. Special Har dened, Precision-ground Washer s Are Included Where Required.