Head Stud Kit

The ARP Head Stud Kit (203-4202) is engineered for enhanced engine reliability and ease of assembly, particularly for performance applications. Each kit includes ten head studs, ten parallel ground washers, and ten 12-point nuts, along with ARP's Ultra-Torque fastener lubricant and installation instructions. The studs are constructed from premium 8740 alloy, heat-treated to a tensile strength of 200,000 PSI. This rigorous heat treatment process ensures complete material penetration, leading to superior performance compared to lesser-quality studs. ARP's manufacturing process involves centerless grinding for exceptional concentricity and thread-rolling after heat treatment, which yields approximately 1000% greater fatigue strength than studs threaded before heat treatment. This robust construction helps prevent blown head gaskets and ensures optimal engine sealing. The use of head studs simplifies engine assembly, especially for racing engines that require frequent servicing. They ensure proper alignment of the cylinder head and gasket and provide more accurate and consistent torque loading. Unlike bolts, studs allow for installation in a relaxed mode, being tightened finger-tight into the block. When the nut is torqued, the stud stretches only on the vertical axis, avoiding the twisting forces experienced when torquing a bolt. This specific kit is designed for the Toyota 1981-1992 Supra 7MGTE engine.