ARP's highest quality Custom Aged 625+ head stud kit specifically made for the Kia & Genesis 3.3T-GDI Lambda II Engines.

This kit includes a set of sixteen Custom Age 625+ head studs, washers, 12-point nuts, and a 1/2 ounce pack of ARP Ultra-Torque fastener assembly lubricant.
 
All Custom Age 625+ studs are centerless ground, heat treated prior to thread rolling and machining, and are nominally rated to 270,000psi. These fasteners deliver a 25-30% increase in tensile strength over the ARP2000 studs & OEM Torque To Yield bolts. 

OEM Bolts - Clamp force of ~16,000 (Tested by Point One Manufacturing)
ARP 2000 - Clamp force of  ~15,000 (Worse than OEM)
ARP CA625+ - Clamp force of ~20,000

This Head Stud kit is engineered to be used with NS300L Block Thread Reinforcement Kit for maximum clamping force, as well as to repair & reinforce the head bolt threads which is proven to be a weak point for aluminum blocks.