ARP uses a premium grade 8740 alloy that is rated far superior to “aircraft” quality. Because ARP studs are manufactured to strict 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.
ARP studs are thread rolled after heat-treat, which gives them about 1000% (that’s ten times) better fatigue strength than those studs that are threaded prior to heat-treat. You will also note that ARP offers specially undercut studs for several engines. This procedure (done only to the shorter studs) more equalizes the “stretch” of both studs, which makes for a more consistent clamping force-one that compensates for head gasket compression when the head is installed. This helps prevent blown head gaskets, and assures optimum sealing!
FITMENT: Mini Cooper S R53 2002-2006
Part Number: 201-4301