ARP 625 head studs installation diesel Houston Drop Forged Diesel
ARP Authorized Installer  ·  Houston, TX

ARP HEAD STUDS
INSTALLER
HOUSTON

ARP 625+ head studs for Cummins, Power Stroke, and Duramax — the insurance policy on every boosted diesel build.
Why We Install ARP

HEAD GASKETS
FAIL. HEAD STUDS
DON'T LET THEM.

Stock head bolts are torque-to-yield fasteners — they stretch once during installation and are designed to be replaced. Under the increased cylinder pressure and thermal cycling of a performance diesel tune, that one-time clamping load isn't enough. Head gasket failures on tuned diesel engines are almost always a fastener problem, not a gasket problem.

ARP 625+ studs are made from a proprietary 8740 chrome moly alloy rated to 200,000 PSI tensile strength — significantly stronger than OEM bolts. Because studs load the block and head in pure tension (no rotational torque during installation), clamping load is uniform across every fastener. The head gasket stays where it belongs.

On any build that adds a performance tune, compound turbo, or upgraded injectors, head studs are not optional. We install ARP on every boosted diesel build we do. We don't tune over stock head bolts on high-output builds. The consequences of a head gasket failure at high cylinder pressure — coolant into the combustion chamber, a hydrolocked engine — are too expensive to risk for the cost of a stud kit.

ARP studs are also reusable across head gasket services, which matters on high-output trucks that see regular maintenance cycles. See our engine tuning page for how head studs fit the overall build sequence, and the turbo and forced induction page for the compound builds where studs are always on the parts list.

ARP 625 head studs installed in diesel engine block Houston
Platform Coverage

ARP Head Studs by Diesel Platform

We install ARP studs on all three major HD diesel platforms. Each has a platform-specific kit and torque specification.

Cummins
5.9 & 6.7
ARP 625+
The Cummins 5.9 and 6.7 are the most common platforms for ARP stud installs because both engines are frequent targets for high-output compound turbo builds. The 6.7 in particular — especially 2019+ trucks running a CP3 conversion and Stage 3 compound turbo — needs studs before pushing past 600 rwhp. The 5.9 12-valve and 24-valve platforms also benefit significantly from studs under any boosted tune over Stage 2.
Ram 2500 / Ram 3500 · 1994–present
Power Stroke
6.0 / 6.4 / 6.7
ARP 625+
The 6.0 Power Stroke is arguably the platform where head studs matter most — the factory 6.0 head bolt pattern is widely regarded as insufficient even at stock power. The 6.4 and 6.7 benefit strongly from studs on any performance build. On 6.0 trucks, studs are part of the standard reliability package regardless of tune level. Head gasket failure on a stock 6.0 is common; on a tuned one without studs, it's expected.
F-250 / F-350 · 2003–present
Duramax
LBZ / LML / L5P
ARP 625+
Duramax head stud installation is standard procedure on any Stage 3 build or compound turbo configuration. The LBZ and LML are common compound and big-injector platforms where cylinder pressure rises significantly above the factory design point. L5P trucks going into Stage 3 territory also get studs as part of the build package. Stage 1 and Stage 2 Duramax builds can run without studs; Stage 3 and above, studs are on the sheet.
Silverado / Sierra 2500 · 2001–present
ARP vs OEM Fasteners

Why ARP 625+ Outperforms Stock Head Bolts

Four specific reasons why ARP studs are the correct fastener for a performance diesel — not a preference, a material and engineering difference.

01
200,000 PSI Tensile Strength
ARP 625+ alloy is rated to 200,000 PSI tensile strength — significantly above OEM torque-to-yield bolts. OEM bolts are designed for factory power levels. A compound turbo build operates at cylinder pressures the OEM engineers didn't design the fastener for. ARP's alloy maintains clamp load at pressures that would cause OEM bolt stretch and loss of sealing force.
02
Pure Tension, No Torque Twist
OEM head bolts apply clamping load by threading into the block while rotating — this introduces torsional stress alongside axial clamping load. Studs thread into the block first, then the nut is torqued down without rotating the stud. The result is pure tension — more accurate, more consistent clamp load across all fasteners, without torsional stress in the shank.
03
Reusable Across Head Gasket Services
OEM torque-to-yield bolts are single-use. Once stretched, they're done — new bolts every time you lift a head. ARP 625+ studs are reusable across multiple head gasket services. On high-output trucks with regular maintenance cycles, this means the stud cost amortizes across multiple service intervals. The only cost on re-use is ARP thread lube and new torque washers.
04
Consistent Clamping Load
OEM bolt clamp load varies because thread friction and torque-to-yield elongation are not uniform across all fasteners. Studs with ARP thread lube allow the nut to be torqued accurately against a known thread friction coefficient. The result is a tighter clamp load variance across the entire head — the gasket sees consistent sealing force at every point, not a variable pattern.
Installation

HOW WE
INSTALL ARP.

ARP head stud installation on a diesel engine requires a complete top-end disassembly. We treat every stud install as an opportunity to inspect everything we'd otherwise never see without pulling the head — deck surface, water jacket condition, coolant passage condition, and valve train components.

On 6.0 Power Stroke trucks in particular, we recommend addressing the EGR cooler and oil cooler at the same time as the stud install — the labor overlap makes it the right time for both. On Cummins builds going into a compound turbo configuration, studs go in before the turbo kit, never after.

All stud installations are torqued in sequence per ARP's published specification for the specific application. We use ARP Ultra-Torque fastening lubricant on all threads and under all nut-bearing surfaces.

01
Top-End Disassembly
Valve cover, intake manifold, turbo (if applicable), and all head bolt / coolant connections removed to access the head bolts.
02
Head Removal & Inspection
Head lifted and inspected — deck surface, fire ring lands, coolant passages. Block deck surface inspected for erosion or cracking. Head gasket condition documented.
03
Stud Installation
ARP 625+ studs threaded into block by hand with ARP Ultra-Torque lube. Studs set to snug contact — no torque applied at stud installation, only at nut torque sequence.
04
Head Gasket & Re-Assembly
New head gasket installed, head lowered onto studs. Washers and nuts installed and torqued in ARP-specified sequence to ARP's specified torque value for the application.
05
Re-Torque After Heat Cycle
On applications where ARP specifies re-torque, a re-torque check is performed after the first full heat cycle. Most diesel applications do not require re-torque, but we verify per the specific application's ARP documentation.
Common Questions

ARP Head Stud FAQ

Questions we hear regularly about ARP stud installation and what triggers the install.

Do I need ARP head studs if I'm only doing a Stage 1 tune?+
On most platforms, Stage 1 power levels — tune only, no compound turbo, stock injectors — do not require ARP studs. The exception is the 6.0 Power Stroke, where we recommend studs regardless of tune level because the OEM head bolt pattern is insufficient even at factory power. On Cummins and Duramax platforms, studs become a standard recommendation at Stage 2 and above. On Stage 3 compound builds across all platforms, studs are required. If you're planning to progress through stages over time, installing studs at Stage 1 saves the labor cost of pulling the head again later.
Can I reuse ARP studs when I replace the head gasket?+
Yes — ARP 625+ studs are reusable across multiple head gasket services, which is one of their key advantages over OEM torque-to-yield bolts. The studs themselves are not consumed during installation. What gets replaced: the head gasket, and optionally the torque washers. The studs are inspected at each service and reinstalled with fresh ARP Ultra-Torque lube. ARP recommends replacing the studs if they show any signs of corrosion, thread damage, or measurement beyond published stretch limits — in normal service, studs outlast multiple gasket changes.
Does a head stud install require the engine to come out of the truck?+
Not on most diesel applications. Cummins, Power Stroke, and Duramax head stud installs are typically performed in-vehicle with the engine in the chassis. The head is accessed by removing the valve cover, intake, and top-end components — the engine does not need to be pulled to complete the install. Labor time varies by platform: the 6.7 Cummins is generally the most straightforward; the 6.0 Power Stroke is more involved due to the EGR cooler and oil cooler work we recommend doing at the same time.
Do I need to replace the head gasket when I install ARP studs?+
Yes. Installing ARP studs requires lifting the head — which requires a new head gasket. You cannot reseal a pulled head gasket. We include a new OEM-spec or upgraded multi-layer steel head gasket with every ARP stud install. The gasket cost is a minor addition to the total install cost, and using a quality head gasket alongside ARP studs is the correct combination — the studs provide the clamping load and the gasket provides the sealing surface. Installing ARP studs with a reused head gasket is not something we do.
ARP head stud installation diesel engine Houston Drop Forged Diesel
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Tell us your platform, current power level, and build goals. We'll confirm whether studs belong in your build now or at your next stage.

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ARP Head Stud Installation — Houston Metro
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