• ARP 4JJ1 head studs by Diesel Performance Parts, high-strength engine fasteners for 4JJ1 diesel engines, shown in the image.
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Diesel Performance Parts

4JJ1 ARP Head Studs

4JJ1 ARP Head Studs

$1,297.00 NZD
$1,297.00 NZD
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Isuzu 4JJ1 ARP2000 Head Stud Kit

🛠️ ARP2000 Alloy 🇺🇸 Genuine ARP 🚚 Free Express AU
Heavy-duty ARP2000 head stud kit designed for Isuzu 4JJ1-TC and 4JX1-TC engines. Provides higher and more consistent clamping force than OEM torque-to-yield bolts — ideal for tuned, boosted, or hardworking engines.
Vehicle Compatibility
  • Isuzu 4JJ1-TC — D-MAX, MU-X, RA7 Rodeo, Colorado RC
  • Isuzu 4JX1-TC applications
What’s in the Box
  • 10 × long ARP2000 studs + nuts
  • 8 × short ARP2000 studs + nuts
  • 18 × hardened parallel-ground washers
  • ARP Ultra-Torque fastener lubricant
  • Printed installation sheet
Installation Instructions
  • Tap block threads to full depth using an M11 × 1.5 bottoming tap (4–5 turns deeper than OEM).
  • Fit head gasket dry over the locating dowels.
  • Use two cut-head bolts as guides and lower the cylinder head into position.
  • Lubricate the block-end of each stud with ARP Ultra-Torque and screw in finger-tight only.
  • Install washers with the bottom face dry and the top face lightly lubricated.
  • Apply ARP lube to the top stud threads and underside of nuts.
  • Fit nuts finger-tight. Back studs off slightly if nuts do not fully engage.
  • Tension in 3 stages following the OEM tightening pattern (example: 40 N·m → 80 N·m → final torque).
⚠️ Important Note – Required Modifications for 4JJ1 Install:

The 8 outer (short) stud locations sit directly under the rocker assembly. There is not enough clearance for ARP washers + nuts without modification.

  • Option 1: Install the 8 short studs without washers.
  • Option 2 (Recommended): Machine washer recesses in the head 3.0 mm deeper.
  • Option 3 (Alternate): Some shops also shorten studs, but this is NOT required.

⚙️ Incorrect clearance will cause rocker interference, improper torque values and poor gasket sealing. Always verify washer + nut clearance before final torque.

For best results, hone cylinders with a torque plate set to your final torque value.

Final Torque Specification

Standard final torque: 122 N·m (90 ft-lb) — approx. 75% of stud yield.

High-load option: 138 N·m (102 ft-lb) — approx. 85% of stud yield.

Why ARP2000 vs OEM Bolts
  • Higher and more consistent clamp load
  • Resists head lift under boost
  • Reusable if within spec
  • Better head gasket sealing
Install Notes & Disclaimers
  • Professional installation strongly recommended
  • Replace head gasket and all single-use seals
  • Retorque only if instructed by your builder
  • For off-road / motorsport use where required by law
CRC Payments & Express Shipping
Payment Options
  • Visa, Mastercard, Amex
  • PayPal, Apple Pay, Google Pay
  • Afterpay, Zip, Klarna, Humm
Express Delivery
  • Free Express Shipping Australia-Wide
  • Same-day dispatch before 12 pm AEST
  • Secure and insured packaging
Frequently Asked Questions (FAQ)
Do I have to machine the head?

For the 8 outer stud locations — YES unless washers are omitted. Machining 3.0 mm deeper is recommended.

Do any studs need shortening?

Not required. Some builders do it, but it is not part of the official procedure.

What torque should I use?

Most builds: 122 N·m. High-load or sealing issues: 138 N·m.

Can ARP studs be reused?

Yes — if undamaged and within manufacturer specification.

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