ARP 625+ Head Stud Kit 11mm

CUTTING EDGE FASTENER TECHNOLOGY

ARP head studs are a critical component for maximum reliability when building for power.  A head stud ensures more accurate torque loading and consistent head gasket clamping forces.  When compared to a traditional head bolt a smaller portion of the fastener torque is wasted in friction and fastener twist so more force can be applied toward sealing the head gasket. Head gasket sealing is more often than not the Achillies heal of building for power. Increased combustion pressures will try to lift the head and reduce the sealing effectiveness of the gasket.

All ARP head studs are centerless ground for concentricity with cold rolled threads for maximum fatigue strength.  Custom Age 625+ alloy has a 260ksi tensile strength making it suitable for higher power applications when compared to the ARP2000 material (we suggest 450bhp limit for ARP2000 and 600bhp for CA 625+).  The studs are undercut to more effectively compensate for head gasket compression.  An allen hex is broached into the end of the stud for easy installation and removal.  These studs are intended for EJ applications but EJ and FA use the same length and thread size meaning these can be used in FA applications without issue.

11mm is the factory thread size so no machine work is required, and they are a direct replacement for the factory head bolts.  It is essential to follow the supplied instructions and use the included ARP thread lubricant.   Use only an accurate torque wrench of known calibration to ensure best results.  Any fastener "spring back" detected at any point during the torque process will require the washer to head surfaces to be meticulously cleaned and the stud re-torqued in order to achieve accurate torque values.

Manufacturer Part Nos. 260-4704

What it fits:

• EJ DOHC