ARP uses a premium grade 8740 alloy, rated far superior to 'aircraft' quality, for their Pro Series cylinder head studs.
Each stud is vertically placed in special racks and precisely heat-treated to 200,000 psi for complete heat penetration.
The studs are then centerless ground to achieve near-perfect concentricity, unlike lesser quality studs.
Due to the exacting tolerances in manufacturing ARP studs, gaskets and cylinder heads will glide into position and align perfectly, which won't occur with inferior quality head studs.
By being thread rolled after heat-treat, these studs exhibit about 1000% (ten times) better fatigue strength than those that are threaded prior to heat-treat, a common industry practice.
Although this method is more costly due to its impact on tooling, the results justify the extra effort.
This cylinder head stud kit includes premium quality parallel ground washers and compact 12-point style nuts for select Mitsubishi applications (2.6 4-cylinder).
