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Head Bolt Kit - 2004-2014 Chevrolet Gen III/IV LS
PART # SKU XP981
Original price
$106.37
-
Original price
$106.37
Original price
$106.37
$106.37
-
$106.37
Current price
$106.37
Availability:
in stock, ready to be shipped
Please note - primary head bolts must all have the same length. There is a Mid-Year split on the head bolts, if you have 2 different size head bolts this kit is NOT for YOU.
DO NOT PURCHASE until you have verified the primary head bolt length.
Please note, when installing our product, the final torque for the 11mm bolts are 80 ft-lbs and NOT 85 ft-lbs as incorrectly noted on our manual
ULTRA STRENGTH
In comparison to standard bolts, our alloy's material characteristics enable much higher tensile strength. For the best fatigue strength, threads are rolled after thermal treatment. A high-quality coating can improve corrosion resistance, reduce friction, and improve overall performance.
EASY INSTALLATION
Installation manual is included with drawn diagrams to ease the installation process. Our head bolts are designed to retain cylinder seal even with today's extremely high-pressure turbo systems.
PREMIUM QUALITY
Black oxide finish protects from wear and tear. Hardened parallel washers allow for uniform load distribution and accurate torque readings.
INSTALL GUIDE
This guide covers installation of the XOTIC PERFORMANCE™ XP981 head bolt kit for 2004+ Chevrolet Gen III/IV LS engines. Prefer a printable copy? Download the PDF manual.
Check your factory bolts before ordering. All of your primary (11mm) head bolts must be the same length for this kit to fit. GM changed the head bolt design mid-year — if your engine has two different lengths of primary head bolt, this is not the right kit. Pull one from each end of a head and compare before you order.
Why upgrade your LS head bolts
Factory LS head bolts are torque-to-yield and single-use — once the heads come off, they're done. If you're replacing them anyway, this is the moment to step up. Cam swaps, nitrous, and boost all raise cylinder pressures well past what the stock hardware was designed to hold, and when the clamping force securing the gasket, head, and block is no longer sufficient, the head gasket lets go.
XOTIC PERFORMANCE™ head bolts are manufactured from our premium XOTIC 7200 steel alloy — far higher tensile strength than standard hardware — and backed by a lifetime warranty. Bolts are the right call when you want strong clamping with the convenience of pulling a head in the chassis without fighting stud clearance. For maximum clamping on a serious boost build, see our LS head stud kit (CP883) and guide. Either way, the key 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 across every bolt.
What's in the XP981 kit
- 20 × head bolts (XOTIC 7200 alloy)
- 20 × hardened parallel washers
- 2 × sockets
- 1 × fastener assembly lubricant
Before you start: verify first
Confirm that part number XP981 is compatible with your application before installing any components. Inspect all package contents for damage and clean as necessary to ensure accurate installation. Report any obvious defects or shipping damage to us before proceeding.
How to install head bolts on a Chevrolet LS
- Clean the block threads. Clean the threads in the block prior to installing the bolts to ensure accurate fitment and precise torque readings. Dedicated chasers make this fast: M11 x 2.00 (CS324) for the primary holes and M8 x 1.25 (CS317) for the small ones.
- Clean the washers and seats. Using a clean cloth, remove all oil from the washers and from the cylinder head surfaces where the washers sit. Clean, dry seating surfaces are essential for accurate preload.
- Set the gasket and head. Install the head gasket and cylinder head.
- Seat the washers — chamfer up. Place the washers on the cylinder head with the chamfered inner diameter facing upward, toward the bolt head. Inspect for any misalignment.
- Lubricate. Using the supplied fastener assembly lubricant, coat the threads of each head bolt and the underside of each bolt head.
- Hand-tighten. Thread the bolts in as tight as can be made by hand.
- Torque in sequence. Follow the torque stages below in the numbered sequence shown in the manual's torque sequence diagram, then repeat on the second bank.
Chevrolet LS head bolt torque specs
11mm bolts (positions 1–10)
| Stage | Torque |
|---|---|
| 1 | 30 ft-lbs |
| 2 | 55 ft-lbs |
| 3 (final) | 80 ft-lbs |
8mm bolts (positions 11–15)
| Stage | Torque |
|---|---|
| Final | 25 ft-lbs |
A common mistake to avoid: when torquing a fastener, do not stop short of the recommended value — continue in one motion until the specified torque is achieved. If you accidentally stop short, loosen the fastener and re-torque. Stopping short and "topping up" produces unequal preload distribution across the bolts and risks joint failure.
Frequently asked questions
What are the torque specs for LS head bolts?
The 11mm bolts (positions 1–10) go to 30, then 55, then 80 ft-lbs in sequence. The 8mm bolts (positions 11–15) torque to 25 ft-lbs.
Which LS engines does the XP981 kit fit?
2004+ Chevrolet Gen III/IV LS engines whose primary head bolts are all the same length. If your engine has a mix of two primary bolt lengths, this kit will not fit — contact us for the right part.
Head bolts or head studs for an LS?
Bolts torque to a lower final spec and let you pull a head in the chassis without dealing with stud clearance — ideal for street builds and cam swaps. Studs deliver maximum clamping for serious boost. If you're going the stud route, see the CP883 head stud guide.
What size thread chasers do I need?
Two: M11 x 2.00 (CS324) for the primary bolt holes and M8 x 1.25 (CS317) for the small ones.
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: 2025.05.26 (web edition 2026.08).
PACKAGE CONTENTS
VEHICLE FITMENTS
⚠️ PROP 65 WARNING
CALIFORNIA WARNING: Cancer and Reproductive Harm -www.P65Warnings.ca.gov
