To overcome head gasket failures that can occur in diesel engines employed in truck and RV applications, industry leader ARP has introduced extra heavy-duty head studs for the popular Ford, Dodge and GM powerplants. These ARP studs are rated at 220,000 psi tensile strength, and provide the clamping force required to keep cylinder heads from lifting due to higher combustion pressures. The studs are manufactured in ARP's Santa Paula, CA plant from proprietary ARP 2000 material, with threads rolled after heat-treat to provide optimum fatigue strength. They are centerless ground to assure perfect concentricity. The ends of the studs are broached to facilitate easy installation. This feature also enables the cylinder head to be removed in tight quarters. Also included in each kit are heat-treated, chrome-moly steel 12-point nuts and parallel-ground washers. They are black oxide finished for extra durability.
INSTALLATION METHOD FOR CUSTOM AGE 625 HEAD STUD KITS
Part Number: 230-4202 Application: Chevy 6.6L Duramax Diesel
Always verify the part number for your application with the part number on the side of box and the part
number on the instruction sheet. This will help ensure you have the correct installation procedure for
your specific application before installing any components.
Clean and inspect all hardware prior to installation. Look for obvious defects or shipping damages, plus proper fit,
length and dimension.
To ensure proper thread engagement and accurate torque readings, clean ALL threads in the block. Chase if
necessary with ARP Thread Chaser, part number 912-0007 (M12 X 1.5) and 912-0001 (M8 X 1.25).
If the cylinder head studs protrude into a water jacket, lubricate the block threads of the studs with ARP THREAD
Screw studs into the block “HAND TIGHT ONLY”.
NOTE: LOCTITE MAY BE USED IF A PERMANENT MOUNTING OF THE STUDS IS PREFERRED. THE
FASTENERS, HOWEVER, MUST BE TORQUED PRIOR TO THE LOCTITE SETTING UP.
Install the cylinder head(s) and check for binding or misalignment.
Lubricate the stud threads, nuts and washers with ARP ULTRA-TORQUE FASTENER ASSEMBLY LUBRICANT.
Then install the washers and the nuts onto the studs and tighten them hand tight. ARP recommends using the
ARP ULTRA-TORQUE FASTENER ASSEMBLY LUBRICANT that is provided with each kit as opposed to
motor oil. This is due to higher friction on the studs as well as inconsistencies in the clamping force of
the fasteners when motor oil or other low quality lubricants are used.
PRELOAD (TORQUE) RECOMMENDATIONS
Following the manufacturers recommended torque sequence tighten the nuts in three equal steps to the
following specifications with ARP ULTRA-TORQUE FASTENER ASSEMBLY LUBRICANT.
M12 150 ft lbs M8 25 ft lbs
Note: ARP Ultra-Torque Fastener Assembly Lubricant has been specifically designed to reduce tension preload scatter and
eliminate the need to cycle high performance engine fasteners before final installation. ARP Ultra-Torque far surpasses all
requirements offered by previous ARP lubricants in terms of fastener preload repeatability and performance lubricating
properties. For more information on ARP Ultra-Torque visit our website at www.arp-bolts.com or call 1 800-826-3045.