ARP 247-4202 Diesel Head Stud Kit (1998.5-2024 Cummins)

Fitment

This kit is listed for the 24-valve Cummins in Dodge Ram and Ram 2500/3500 pickups: the 1998.5-2002 5.9L, the 2003-2007 5.9L common rail, the 2007.5-2012 6.7L, the 2013-2018 6.7L and the 2019-2024 6.7L. ARP calls it a direct fit for 24-valve 5.9L and 6.7L Cummins engines, and ARP's own copy for this kit lists 1998.5-2023, so verify fitment by VIN if you have a 2024. This listing stops at 2024; if your truck is a 2025 or newer, call us before you order. The earlier 12-valve 5.9L is not part of this listing. You can find more parts for your engine on our Cummins page, or send us your VIN and we will confirm the fit.

Why this part

ARP's view is simple: factory head bolts are the weak link in a diesel engine, especially one that has been modified. ARP points out that most engines are assembled at the factory with torque-to-yield (TTY) bolts that are preloaded to yield and beyond, typically 100-110%. That leaves little margin. Any increase in combustion pressure can lead to problems like blown head gaskets or catastrophic engine failure. And because TTY bolts are yielded by design, ARP says they should never be re-used.

Head studs fix the clamping side of that problem. A stud gives the engine the clamping force it needs to keep the cylinder head from lifting under higher combustion pressure. That is why head studs are the usual fix for a lifted head on a Cummins making more boost than the factory fasteners were built for, and why they belong on the list before the truck sees more boost or bigger injectors.

What you get

• ARP 247-4202 head studs made from ARP2000 alloy with a black oxide finish
• Chrome moly steel 12-point nuts
• Hardened parallel ground washers for even load distribution and accurate torque readings
• 0.5oz of ARP assembly lubricant

Specifications

ARP starts with its ARP2000 alloy, which ARP rates far above aircraft-quality alloy steels. ARP2000 shares similar traits with Chrome Moly 8740, but it can be safely heat treated to a higher level, so the finished stud is stronger and reaches a higher clamp load, at 220,000 psi.

Each stud is placed vertically in special racks and heat-treated so the heat penetrates completely, instead of parts being dumped in a basket. The studs are then centerless ground so they are concentric, which takes as many as ten machining steps. Threads are rolled to MIL-S-88794 specs after heat treatment. ARP says that gives about 2000% (twenty times) better fatigue strength than studs threaded before heat treat. It costs more and is tough on tooling, but ARP does it for the fatigue strength. The studs are shot-peened to remove surface irregularities and improve external integrity, and the final black oxide coating is applied in-house at ARP for long-lasting corrosion resistance.

ARP's feature list for this kit:

• Proprietary ARP 2000 Material
• Rated At 220,000 Psi Tensile Strength
• Includes Chrome Moly Steel 12-Point Nuts
• Black Oxide Coating For Added Corrosion Resistance
• Centerless Ground To Ensure They Are Perfectly Concentric
• Improved Clamping Force Prevents Cylinder Heads From Lifting
• Broached Stud Ends Install & Make Cylinder Head Removal Easier
• Heat-Treated Prior To Thread Rolling And Machining For Optimum Fatigue Strength
• Shot-Peened To Remove Any Surface Irregularities And Improve Overall External Integrity
• Hardened Parallel Ground Washers For An Even Load Distribution And Accurate Torque Readings
• Comes With 0.5oz Of ARP Assembly Lubricant

About ARP

ARP (Automotive Racing Products) was founded in 1968 and is based in Ventura, California. It builds heavy-duty head studs and fasteners for racing, performance and a wide range of diesel applications, and ARP says virtually every top professional engine builder relies on its head studs for all-out competition engines. This kit uses ARP2000; ARP also offers a Custom Age 625+ head stud kit for 1998.5-2024 Cummins.

Frequently asked questions

Can I reuse my old head bolts instead?

ARP's guidance is that torque-to-yield bolts are yielded by design and should never be re-used. Studs also give more clamping force than standard bolts, which is what keeps the head from lifting once you add boost.

Does one kit cover both the 5.9L and the 6.7L?

Yes. ARP lists 247-4202 as a direct fit for 24-valve 5.9L and 6.7L Cummins engines in Ram 2500/3500 pickups. Our listing runs 1998.5-2024; send us your VIN for a 2024 or anything newer.

What hardware comes with the studs?

The kit includes chrome moly steel 12-point nuts, hardened parallel ground washers and 0.5oz of ARP assembly lubricant. The washers spread the load evenly and help you get accurate torque readings.

Questions on fitment? Call the shop at the number in the header. We install everything we sell.