As you increase the power output of your engine beyond its factory specifications, the head and block may start to separate, causing factory bolts to stretch and fail. Our ARP Head Studs are designed to be stronger than factory bolts, ensuring your race engine stays together even under extreme conditions.

Our Custom Age 625+ kit is made from a material with a tensile strength of 260 ksi, substantially higher than the 190 ksi of the ARP 2000 head stud. It’s an ideal choice for individuals who want to push the limits of their S58 builds.

1. To ensure proper thread engagement and accurate torque readings, clean ALL threads in the block. Chase if necessary with ARP Thread Chaser.

2. Clean and inspect all hardware prior to installation. Look for obvious defects or shipping damages, plus proper fit, length and dimension.

3. If the cylinder head studs protrude into a water jacket, lubricate the block threads of the studs with ARP THREAD SEALER.

4. Screw studs into the block “HAND TIGHT ONLY”.

5. Install the cylinder head(s) and check for binding or misalignment.

6. 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

7. Following the manufacturers recommended torque sequence tighten the nuts steps 1-3

with ARP Ultra-Torque fastener assembly lubricant

12	10	4	2	6	8	14
13	7	5	1	3	9	11