The Manley Turbo Tuff Connecting Rods are a favorite for many high power engine builders. They are known for their exceptional strength and the ability to hold extreme power without issues even past the 1000whp mark. The rods are forged from 4340 vacuum degassed material. Each are fully machined at Manley's factory in Lakewood, NJ and adhere to Manley's strictest standards. Their signature "Turbo Tuff" design combines the correct weight and durable strength for ultimate horsepower applications. After machining, each rod is shot peened and magnafluxed. The bores are round with no taper and the bend and twist in the rods are tightly controlled. The cap fasteners used are 3/8" ARP 2000 cap screws.