Product Description
The HAISLEY MACHINE HMR 1054005XL 14MM EXTRA LONG MAIN STUD KIT is engineered for serious Cummins engine builds where block stability and bottom-end strength are critical. Designed for high-horsepower diesel applications, this heavy-duty fastener kit replaces factory main bolts with ultra-strong 14mm x 2.00 extra-long main studs that dramatically improve crankshaft main cap retention under extreme cylinder pressure.
Manufactured for Haisley Machine by ARP, the studs feature premium alloy steel construction, a durable black oxide finish, and a hex broach design for easy installation. The extra-long 7.250" studs are specifically intended for use with modified girdle kits, allowing the main caps to be tied directly to the block for improved rigidity in high-boost and competition diesel engines.
Each kit includes hardened 12-point nuts, heavy-duty washers, and installation instructions. This upgrade is ideal for performance builds including street performance trucks, sled pulling engines, and high-boost Cummins race builds where block flex must be minimized.
Important installation note: Many 1997.5+ Cummins "Encore" blocks originally use 12mm main hardware and must be drilled and tapped to 14mm x 2.00 threads before installing this stud kit.
Fitment
- 1989–1993 Dodge Ram 5.9L Cummins (1st Gen 12 Valve)
- 1994–1998 Dodge Ram 5.9L Cummins (12 Valve)
- 1998.5–2002 Dodge Ram 5.9L Cummins (24 Valve)
- Compatible with performance Cummins engine builds utilizing main girdle reinforcement
Frequently Asked Questions
What is the advantage of upgrading to 14mm main studs?
Larger diameter studs provide significantly greater clamping force than factory bolts, helping prevent main cap movement and block distortion in high horsepower diesel engines.
Why are these studs extra long?
The extra length allows the studs to pass through a modified main girdle system which ties the main caps to the engine block for additional structural reinforcement.
Do all Cummins engines accept these studs?
Most 1989–2002 Cummins blocks can use this kit, but 1997.5+ Encore blocks may require drilling and tapping from the factory 12mm threads to 14mm x 2.00 threads before installation.
Who manufactures these studs?
These studs are manufactured for Haisley Machine by ARP, one of the most trusted names in high-performance engine fasteners.
Is this kit recommended for high horsepower builds?
Yes. Performance builders commonly use this upgrade in competition diesel engines, high boost street builds, and engines running girdle reinforcement systems.
Specifications for HAISLEY MACHINE HMR 1054005XL
| Specification | Details |
|---|---|
| Brand | Haisley Machine |
| Part Number | HMR 1054005XL |
| Stud Size | 14mm x 2.00 |
| Stud Length | Extra Long – approx. 7.250" |
| Material | High-strength alloy steel |
| Finish | Black Oxide |
| Hardware Included | 12-Point Hardened Nuts and Heavy-Duty Washers |
| UPC | Not Available |
| GTIN | Not Available |
| Shipping Weight | Approx. 12 lbs |
| Prop 65 Warning | May contain chemicals known to the State of California to cause cancer or reproductive harm. www.P65Warnings.ca.gov |
