ARP Header Bolts 3/8 in x 1.000 in Black Oxide — Set of 16, Chrome‑Moly 170,000 psi

When fitting or replacing exhaust headers you want fasteners that resist stretch and hold torque under repeated heating cycles. ARP manufactures these 3/8" diameter, 1.000" under-head length bolts entirely in-house to tight tolerances, producing a kit that includes premium washers and is rated at 170,000 psi tensile strength — significantly higher than typical Grade 8 hardware. The black oxide finish provides surface protection and a low-profile aesthetic that pairs well with most engine bays.

How do these bolts improve exhaust header installation?

These bolts are designed to maintain clamping force as the header and cylinder head cycle through heat and cool phases. The high tensile rating reduces the risk of bolt stretch or failure, while the consistent under-head length ensures proper engagement without bottoming out in blind holes.

• Heat-treated 8740 chrome-moly steel for superior strength
• 170,000 psi tensile rating minimizes elongation under load
• 1.000" under-head length fits common header stud depths
• Includes premium washers for even load distribution

Are these bolts compatible with my vehicle’s header studs?

The ARP 100-1110 set uses a 3/8" diameter with a conventional hex head, matching many OEM and aftermarket header stud setups. Confirm stud thread size and head clearance on your application; these bolts are intended for use where a 1.000" under-head engagement is appropriate.

• 3/8" bolt diameter suits standard header studs and bolts
• Hex head fits common sockets and wrenches for easy installation
• Black oxide finish reduces glare and offers mild corrosion resistance
• Pack of 16 covers most V6/V8 header layouts or full replacement needs

What makes ARP’s manufacturing different?

ARP controls the entire production process to uphold their "zero defects" standard, performing heat treatment and finishing in-house to ensure consistent material properties and dimensional accuracy. That in-house approach reduces variability and delivers repeatable performance across every kit.

• Full in-house manufacturing and quality inspection
• Heat-treated to precise hardness and strength specs
• Black oxide finishing applied for uniform appearance and protection
• Each kit includes matched washers for predictable clamping

How should I install and torque these header bolts?

Use a calibrated torque wrench and follow your header or engine manufacturer’s torque sequence and values. These bolts accept common torque procedures but always use the recommended torque and, if required, an appropriate thread lubricant or anti-seize specified by the engine maker.

• Follow a crisscross torque pattern to seat flanges evenly
• Verify torque specs from the header or engine manufacturer
• Use matching washers included in the kit for consistent clamp
• Inspect bolts for correct engagement and re-torque if specified

Who this is for: The ARP 100-1110 header bolt set suits mechanics, performance builders, and DIY enthusiasts who need durable, high-strength fasteners for exhaust header projects. It’s appropriate for restorations, upgrades, and race-prep work where improved tensile strength and consistent manufacturing quality matter. Confirm thread compatibility and required under-head length for your specific application before ordering.