One of the most common upgrades out there! ARP Head Stud Kit 247-4204 for your 1998.5 to 2018 Cummins 5.9/6.7. We recommend going with ARP Head Studs on every single diesel application due to the tremendous cylinder pressures these engines experience, because of this we feel that head bolts are just not sufficient for the application. These studs will be PLENTY of clamping force to keep your head gasket in one piece even under the most strenuous conditions!
ARP 2000 vs ARP 625 Argument:
We get this question quite a bit… Do I need 625’s? The simple answer, is that the ARP2000 and 625 styles are both a very capable fastener. The BIGGEST difference is that the ARP2000 is made out of a material that will eventually rust, and the 625’s are not. The 625’s per the material do have a higher “clamping force” however, we have never broken a stud before from either style. We have found that you will pull the threads out of the block before you break a stud! Typically as a rule of thumb, we go with 625’s for those “wild” 1200+ HP combinations, for anything else? ARP2000’s will do.