Factory main bolts can be a weak link when cylinder pressure climbs. Stronger main studs help keep the bottom end locked in place under load.

The ARP 247-5404 main stud kit is for 3.9 Cummins 4BT. It replaces stretch-prone hardware with ARP fasteners built for high-load diesel use.

What you get

• ARP2000 material (typical tensile ~220,000 psi per ARP)
• ARP main stud kit
• Fitment: 3.9 Cummins 4BT
• Follow ARP installation instructions for your exact kit

Specs

• ARP part number: 247-5404
• Material: ARP2000
• Typical tensile strength: ~220,000 psi (ARP material data)

A solid choice for rebuilds and higher-power diesel bottom-end work. Install with the ARP instruction sheet for 247-5404—use the supplied lubricant and torque or stretch procedure. Verify fitment for your exact engine and year before ordering.