Toyota Supra 2JZA80 head stud kit Head studs hold your head and block together. As you make more power than your engine was designed to hold from the factory, the head and the block push apart from each other, stretching the factory bolts, and causing various failures. ARP Head Studs are stronger than the factory fasteners, and are designed to keep your race engine together under any circumstance. Factory fasteners were not designed for performance use. The material is not optimum for a high reving, high heat, high power, race car. The factory fasteners were also not designed to be reused. Every time you torque a fastener, it stretches to perform the proper clamping force. If the fasteners stretch too far, they will not longer provide the required clamping force, and can lead to an engine failure. When you take your factory engine apart to build it into your race engine, discard your used factory main bolts and switch to a brand new set of ARP Head Studs to provide your engine with the proper clamping force required to keep all of your parts together in the harshest race environment. We have seen heads lift and blow head gaskets, pressurize the cooling system, and worse. ARP Head Studs are a very inexpensive part that couldn’t be more important to your engine build. Consider them a must. These head studs are manufactured from premium 8740 chrome moly steel and heat treated to 200,000 psi. They are thread rolled after the heat treating process, which vastly improves their fatigue tolerance compared to studs threaded before heat treatment. High-quality, parallel ground washers included. Exact tolerances ensure that gaskets and cylinder heads just glide into position and align perfectly. Please message us for a Return Authorization Number before sending anything back to avoid processing delays. Real Street Performance is unlike most “Race Shops”. We are a fully functioning wholesale and retail distribution warehouse in addition to a dyno-equipped tuning and engine building facility. Our sales center and order fulfillment center operates with state of the art, industry leading software that allows us to get you ALL of the parts you need for your build quickly and correctly the first time without the headaches or excuses. Sign up to our Newsletter.