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ARP Custom Age 625+ Head Stud Kit

MODEL # ARP260-4704


  • Q: Diameter  tabz991 year ago

    May I know what are the diameter of these studs? is it 11 or 14mm? tnx!
  • Q: Tensile Strength rating  SubZero6 years ago

    Description says typical tensile strength is 260,000-280,000 psi. Are these for people who can't sleep at night? I'm asking because with my build, I'd like to run 25-35 psi through a BW EFR 8374 and the ARP 11mm head bolts have a tensile strength to 200,000 psi and are 66-90% cheaper if these weren't on sale for $695. So I guess my question is, Do I need these?
    • 0 of 0 people found the following answer helpful

      A:  High cylinder pressures will start lifting heads on the car, so that is the reason of why people will start upgrading to these units over the standard ARP studs. Variables such as ignition advance and boost pressure will play a huge role in cylinder pressures that cause this to occur. But as a rule of thumb, we have customers who plan on running over 500WHP and/or 28PSI+ boost pressure out of a medium to large frame turbo to upgrade to these.

      Kirill C. @ RallySport Direct 6 years ago  
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  • Q: Torque Spec  Arty2026 years ago

    Factory bolts are torque to yield correct? These I assume are not torque to yield. So what torque spec do these get?
    • 0 of 0 people found the following answer helpful

      A:  The factory head bolts are torque to yield and these studs are torqued in the same sequence, but there are different steps. You will want to first clean the threads in the block and you may need a M11 X 1.25 thread chaser. You can then install the head studs hand tight in the block and set the heads in place. 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. Following the manufacturers recommended torque sequence tighten the nuts in three equal steps to 100 ft lbs. The most common torque specs are first 30, then 60 and finally 100 ft lbs.

      Zach G. @ RallySport Direct 6 years ago  
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