ARP uses a premium grade 8740 alloy rated far superior to 'aircraft' quality for their cylinder head studs in the Pro Series.
Each stud is placed in special racks vertically and heat-treated precisely to 200,000 psi for complete heat penetration.
The studs are then ground centerless to achieve 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.
These studs are thread rolled after heat-treat, resulting in about 1000% (ten times) better fatigue strength compared to studs threaded before heat-treat, a common industry practice.
Although this method is more costly and tough on tooling, the results justify the extra effort.
This cylinder head stud kit features undercut studs to equalize the 'stretch' for a more consistent clamping force, helping to prevent blown head gaskets, and includes premium quality parallel ground washers and compact 12-point style nuts for select Ford small block applications (351W with factory heads, M-6049-J302, SVO high port and M-6049-L302 GT-40 style, Edelbrock aluminum and Iron Dart with 1/2-13 cylinder block threads).
