ARP Complete Main Stud Kit

There are many important reasons to use ARP Main Stud Kits on your 1984-89 Nissan 300ZX & 300ZX Turbo (Z31 Chassis), including the elimination of main cap walk and fretting, as well as protecting the threads in your engine block.

ARP uses a premium quality 8740 chrome moly steel alloy that is rated superior to aircraft quality. Each stud is placed vertically in special racks and heat-treated to ensure 360° penetration. This procedure is far superior to other methods of dumping items in a large bin and batch treating.

Following heat-treatment, each stud is shot-peened to remove surface irregularities, and then undergoes a centerless grinding process to ensure they are perfectly concentric. This procedure involves about ten machining steps for an exceptionally straight part.The studs are then thread rolled after heat-treatment, which gives them about 1000% (10 times) more fatigue strength than those studs that are threaded prior to heat-treatment.

ARP Fastener Nuts are manufactured in a multi-step process that “blanks” the hex and 12-point nuts and is followed by a CNC-threading process which taps each nut with an accuracy of .001K (5 times higher than the aerospace standard). This ensures an exceptionally close-tolerance fit between the bolt/stud and nut.

This main stud upgrade kit for your Z31 300ZX engine includes:

• Eight (8) ARP Main Studs
• Eight (8) ARP Fastener Nuts
• Eight (8) ARP Premium Parallel-Ground Washers