YD25 Diesel ARP Head Stud Kit Nissan

For good reason, virtually every top professional engine builder relies on ARP Pro Series head studs for their all-out competition powerplants.

Simply stated, there is not a better stud setup on the market today.

For openers, a premium grade 8740 alloy that is rated far superior to aircraft quality is used by ARP.

Each stud is placed vertically in special racks and precisely heat-treated to 200,000 psi.

This procedure ensures complete heat penetration, and the results are far superior to those lesser quality studs from other manufacturers who just dump pieces in a basket and hope for the best.

Following heat-treat, each stud is centerless ground to make it as close to perfectly concentric as possible.

This procedure involves about ten very slight cuts and results in an exceptionally straight part.

It's important to note that lesser quality studs are not even centerless ground; the material is thread rolled in bar stock form, mostly before heat-treat when the material is easier to machine.

Because ARP studs are manufactured to such exacting tolerances, you will note that gaskets and cylinder heads literally glide into position and are perfectly aligned, something that won't happen with inferior quality head studs.