ARP 247-4204 Custom Age 625+ Head Stud Kit 1998.5-2024 Dodge RAM 2500/3500 5.9L/6.7L Cummins

ARP 247-4204 Custom Age 625+ Head Stud Kit – 5.9L / 6.7L Cummins

When cylinder pressure goes up, factory hardware becomes the failure point.

The ARP 247-4204 Custom Age 625+ Head Stud Kit is built for high-horsepower and competition-level 5.9L and 6.7L Cummins engines. Designed to replace weak factory torque-to-yield (TTY) head bolts, this kit delivers the clamping force required to keep the cylinder head sealed under extreme combustion pressure.

If you’re pushing boost, adding fuel, or building for reliability under load, head studs aren’t optional—they’re required.

Why It Matters

OEM head bolts are designed to stretch and yield during installation. That works fine for stock applications, but once power levels increase, they become a liability.

Higher cylinder pressures can lead to:

• Head lift

• Blown head gaskets

• Loss of compression

• Catastrophic engine failure

ARP head studs eliminate that risk by providing consistent, reusable clamping force that holds everything together when it matters most.

Performance Benefits

The Custom Age 625+ material is where this kit separates itself.

Manufactured from a high-strength chromium-cobalt nickel alloy, these studs are engineered for extreme environments where standard materials fall short.

• Significantly higher fatigue strength than traditional studs

• Superior resistance to heat, corrosion, and oxidation

• Maintains clamping force under extreme cylinder pressure

• Proven performance in high-horsepower and competition builds

With tensile strength rated between 260,000–280,000 psi and yield strength between 235,000–255,000 psi, these fasteners outperform Chrome Moly 8740 and ARP 2000.

Precision Manufacturing

ARP doesn’t cut corners—and it shows in the process.

Each stud goes through a multi-step manufacturing process designed to maximize strength and consistency:

• Precision heat-treated in vertical racks for complete penetration

• Centerless ground for perfect concentricity

• Threads rolled after heat treatment for up to 20x greater fatigue strength

• Shot-peened to eliminate surface imperfections

• Finished with a black oxide coating for corrosion resistance

The result is a fastener that performs under pressure—literally.

Key Features

• Custom Age 625+ high-strength super alloy

• 235,000–255,000 psi yield strength

• 260,000–280,000 psi tensile strength

• Chrome Moly steel 12-point nuts included

• Black oxide coating for corrosion resistance

• Centerless ground for precise fitment

• Increased clamping force to prevent head lift

• Broached stud ends for easier installation and removal

• Heat-treated before machining for maximum durability

• Thread rolled after heat treat for superior fatigue strength

• Shot-peened for improved structural integrity

• Hardened parallel-ground washers for accurate torque and load distribution

• Includes 0.5 oz ARP fastener assembly lubricant

Fitment / Compatibility

• 1998.5–2024 Dodge Ram 2500 / 3500

• 5.9L Cummins (24-valve)

• 6.7L Cummins

Bottom Line

There’s a reason top engine builders rely on ARP.

If you’re increasing power, towing hard, or building for competition, this is one of the most critical upgrades you can make to keep your engine sealed, reliable, and performing at its peak.