Hi Rick,

The failures using ARP bolts are the result of incorrect procedures - not the fastener.
Why would Formula 1, Nascar, and other professional series use ARP studs for engine assemblies if they were inferior? That is just silly. The metallurgy is simply superior.

The reason stretch bolts were introduced by mass manufacturers was to eliminate the
retorquing that was necessary with a non-stretch fastener and easier for automated engine assembly . Do you realise how a stretch bolt is designed to operate? It is made of a lower grade material - grade 8 or lower, and is torqued over the maximum yield point at which the fastener reaches a plastic stage. There is alot of published material on the subject.

Again, for some applications (lower stress) the stretch to yield bolt is perfectly fine.
Putting in a better fastener may be overkill, as are forged pistons and steel rods, but
for that extra insurance and a much longer mean time between failure.....