High strength ARP stainless reduced shank studs and bolts for head and cylinders.
The fluted shanks allow the studs to stretch to prevent the threads from pulling out. The stretch keeps bolts and studs tight to help prevent oil leaks because they can stretch and contract along with the motor as it heats up and cools down. Also prevents bolt/stud breakage. Special triangular reduced shank studs help align the head with the cylinders. “Fluting” the sides of the bolts is superior to reducing the diameter because there is less “twisting” when torquing down. Stock heads should have US 3/8″ coarse thread TimeSerts installed. Full Auto heads with British thread Helicoils need conversion to US threads with oversize TimeSerts (“Big-Serts”).