This guide covers installation of the XOTIC PERFORMANCE™ CP875 head stud kit for the 2008–2010 6.4L Ford Power Stroke (F250, F350, F450). It includes the three-stage M16 torque specs, the M8 inner row bolt procedure, and the prep steps that determine whether your head gaskets seal. Prefer a printable copy? Download the PDF manual.

Why the 6.4L Power Stroke needs head studs

Factory OEM head bolts are torque-to-yield: you torque them to a specified value, then add a final 90° rotation that stretches the bolt to its maximum point. That works at stock power levels. But when you add parts that increase horsepower — a turbocharger, injectors, a tuner — you create higher cylinder pressures lower in your RPM range, and the clamping force securing the gasket, head, and block is no longer sufficient. The result: a blown head gasket.

Head studs are engineered to resist stretching. XOTIC PERFORMANCE™ head studs are manufactured from our premium XOTIC 7200 steel alloy, superior in tensile strength to any bolt, and backed by a lifetime warranty. The key to getting that strength into your engine is accurate preload — the tensile force generated when a fastener is tightened, creating clamp force in the joint. Everything in this guide is in service of achieving equal, accurate preload on all 20 studs and 10 inner row bolts.

What's in the CP875 kit

• 20 × M16 head studs (XOTIC 7200 alloy)
• 10 × M8 inner row bolts
• 30 × hardened parallel washers
• 20 × nuts
• 1 × socket
• 1 × allen wrench
• 1 × fastener assembly lubricant

Before you start: verify first

Confirm that part number CP875 is compatible with your application (2008–2010 6.4L Ford Power Stroke — F250, F350, F450) before installing any components. Inspect all package contents and clean as necessary to ensure accurate installation. Report any obvious defects or shipping damage to us before proceeding.

How to install head studs on a 6.4L Power Stroke

1. Clean the block threads. Clean the threads in the block prior to installing the head studs to ensure accurate fitment and precise torque readings. Dedicated thread chasers make this fast and protect the threads — see CS301 and CS317 (M8 x 1.25) in our catalog.
2. Install the studs hand-tight. Thread the head studs into the block by hand until snug. Do not apply torque.
3. Check stud height with a straightedge. Use a straightedge ruler to measure the distance from the mating surface (deck or main cap) to the top of each installed stud. Ensure all studs of the same length group sit level with each other (within 1 mm / 0.040”). Uneven height may indicate debris or incorrect thread engagement. Properly installed studs will bottom out smoothly and show uniform height across all positions. If a stud appears higher or lower than the others, remove it, re-clean the hole, and reinstall by hand. Do not use tools to force studs deeper. Incorrect stud seating can cause off-angle stress, uneven preload, or stud fracture during engine operation.
4. Set the gasket and head. Install the head gasket and cylinder head, ensuring proper alignment.
5. Clean the washer seating areas. Clean the washer seating surfaces on the cylinder head with a fast-evaporating solvent such as non-chlorinated brake cleaner to remove oil, grease, and contaminants. A clean surface is essential for achieving proper fastener preload.
6. Lubricate. Place the washers onto the studs. Using the supplied assembly lubricant, apply a thin coat to the stud threads, the underside of the nuts, and the top side of the washers.
7. Install the nuts. Thread the nuts onto the studs and hand-tighten until they make contact with the washers.
8. Set the inner row bolts. Apply assembly lubricant to the threads and the seating surface of the M8 inner row head bolts. Seat the washers onto the cylinder head, then thread in the bolts and hand-tighten only. Do not torque yet.
9. Torque in sequence. Follow the torque stages below in the numbered sequence shown in the manual's torque sequence diagram.

6.4L Power Stroke head stud torque specs

M16 head studs (positions 1–10, three stages)

M8 inner row bolts (positions 11–15)

After the M16 studs reach final torque, torque the M8 inner row bolts in positions 11 through 15 to 25 ft-lbs.

Frequently asked questions

What are the torque specs for 6.4L Power Stroke head studs?

M16 studs (positions 1–10): three stages — 90 ft-lbs, then 180 ft-lbs, then a final pass at 275 ft-lbs, in the numbered sequence. M8 inner row bolts (positions 11–15): 25 ft-lbs after the studs are fully torqued.

What trucks does the CP875 kit fit?

2008–2010 Ford Super Duty trucks with the 6.4L Power Stroke: F250, F350, and F450.

Does the 6.4L use inner row bolts like the 6.0L?

Yes — the kit includes ten M8 inner row bolts (five per head, positions 11–15). They install with lubricant on both the threads and the seating surface, with washers seated on the cylinder head, and torque to 25 ft-lbs after the main studs reach final torque.

What size thread chaser do I need for a 6.4L head stud install?

The manual references CS301 for the stud holes and CS317 (M8 x 1.25) for the inner row bolt holes — both available in our catalog.

Doing the full engine?

If the heads are off, it's the cheapest time you'll ever have to do the bottom end. The Head & Main Stud Combo Kit (CP875-MP875) pairs these head studs with the MP875 main stud kit in one package.

Related install guides

Working on a 6.0L instead? See our 6.0L Power Stroke head stud installation guide (CP874).

Need help?

For technical support, email support@xotic-performance.com. All XOTIC PERFORMANCE™ fasteners are covered by our limited lifetime warranty. Finished your install? Tag #XOTICPERFORMANCE on Instagram for a chance to be featured.

© 2026 XOTIC PERFORMANCE™. This installation guide is an original copyrighted work of XOTIC PERFORMANCE™. Reproduction, distribution, or use of this content in whole or in part without written permission is prohibited. Doc ref: 2025.05.27 (web edition 2026.08).