ARP Con Rod Bolt Kit - 9mm - 4A-GZE & 4A-GE 16 & 20 Valve EnginesARP Con Rod Bolt Kit 9mm Applications include 4A GZE & 4A GE 16 & 20 Valve Engines. The ARP Con Rod Bolt Kit is a must have when pushing performance in high boost forced induction or high compression, high rpm engine builds. ARP is the market leader in fasteners and bolts for racing and high performance engines. ARP's Top quality, exact tolerances, and use the best materials and machining processes, as well as the ability to survive the rigours of