Reinforced head studs with low elongation help prevent gasket leakage problems caused by head lifting due to high combustion pressure.

■Features

• “Reinforced Head Studs” are now available to prevent gasket leakage due to head bolt elongation caused by high combustion pressure in highly modified engines.
• Evaluation was conducted through actual driving tests at high output of more than 1,200ps in drag racing.
• In order to meet the recent demand for higher power output of RBs, the “Custom Age 625+” material with the higher tensile strength is used, and HKS‘ original bottom tapping design is to reduce the damage to the block.
• Custom Age 625+ material has the highest tensile strength of all ARP materials and has outstanding anti-corrosion and fatigue life. It has approximately 1.3 times the tensile strength of the ARP2000 material, which prevents problems such as gasket leakage even at high combustion pressures.
• By using bottom tapping stud bolts, the thread engagement on the block side are longer, stress is dispersed, and cracks are less likely to occur around the threaded holes on the deck.
• By reducing the risk of cracking, it also contributes to extending the life of the cylinder block, which is now very valuable. It is recommended not only for highly modified engines, but also for general overhaul.
• By using this product with HKS head gaskets, it will provide a more effective sealing effect. Especially for those who are aiming for high output or for race track driving, we recommend using this product in combination with “Grommet Type Metal Head Gasket Super Cooling”.

ARP Custom Age 625＋material

Bottom tapping stud

Vehicle	Model	Engine	Model Year	Code No.	Manual	Remarks
SKYLINE GT-R	BCNR33	RB26DETT	95/01 -98/12	22999-AN008