ARP Header Bolt Kit – Chevy LS & LT | 3/8"-16 Flange Hex | 16-Piece | 134-1102

ARP 134-1102 — the definitive header bolt kit for Chevy LS and LT engine builds. 3/8"-16 flange hex bolts in a complete 16-piece kit for V8 LS/LT header installation. ARP-grade alloy construction with integrated washer flange — rated for the extreme thermal cycling of exhaust applications. Made in the USA by ARP. Ships fast across Canada and the US.

Why ARP Header Bolts — vs OEM or Generic Hardware

Header bolt selection matters more than most builders recognise. The exhaust header is one of the highest thermal-stress bolted joints in the engine:

• OEM LS exhaust manifold bolts — torque-to-yield: Many LS engine variants use torque-to-yield (TTY) exhaust manifold bolts from the factory. TTY bolts are engineered to stretch plastically during installation to a precise clamp load. They are single-use — once stretched, they must not be reused. When installing aftermarket headers, the OEM TTY bolts are removed and should not be reinstalled. ARP 134-1102 replaces them with reusable, non-TTY fasteners rated for header use.
• Generic grade 5 / grade 8 hardware: Standard hardware store bolts are not manufactured to the dimensional consistency, surface finish, or alloy specification of ARP fasteners. In an exhaust application, generic hardware loosens through vibration, galls in aluminium cylinder heads on removal, or fatigues and fails under repeated thermal cycling from ambient to operating temperature. ARP’s alloy and surface treatment are specifically selected for exhaust temperature tolerance and resistance to heat-cycle loosening.
• ARP alloy and surface treatment: ARP 134-1102 uses ARP’s proprietary alloy (typically 8740 chrome moly or stainless depending on the specific production run — confirm in ARP’s current catalogue). The black oxide or stainless finish resists corrosion and prevents galling when threading into aluminium LS/LT cylinder heads. The integrated flange distributes clamp load over a larger bearing area than a standard hex bolt, reducing the risk of header flange deformation and improving sealing consistency across the exhaust port face.

3/8"-16 Flange Hex — Specification Detail

• 3/8"-16 UNC thread: 3/8 inch diameter, 16 threads per inch (coarse thread, UNC). This is the standard exhaust port bolt thread for all LS and LT cylinder heads. Aftermarket LS headers are threaded to this specification as standard across virtually all manufacturers (Hooker, Kooks, American Racing Headers, Hedman, etc.).
• Flange hex head: The integrated washer flange below the hex eliminates the need for a separate flat washer, prevents bolt rotation-induced loosening (the flange resists spinning on the header flange surface), and cannot be lost during disassembly. Flange bolts are the preferred format for header installation on aluminium heads.
• Hex drive: Standard 6-point hex — accepts a 9/16" hex socket for installation and removal. Accessible in most LS engine bay installations with a standard 3/8" or 1/2" drive ratchet and socket.

LS / LT Engine Family Coverage

ARP 134-1102 fits all production GM LS and LT V8 engines sharing the standard 3/8"-16 exhaust port thread:

• Gen III LS: LS1 (5.7L — Corvette C5, Camaro F-body, GTO), LS6 (5.7L — Z06 Corvette, CTS-V), LQ4/LQ9 (6.0L — Silverado, Sierra HD)
• Gen IV LS: LS2 (6.0L — C6 Corvette, GTO, Trailblazer SS), LS3 (6.2L — C6 Corvette, Camaro SS), LS7 (7.0L — Z06 Corvette), LS9 (6.2L supercharged — ZR1), LSA (6.2L supercharged — CTS-V, Camaro ZL1), L92/L99/L76 (6.2L/6.0L — trucks and SUVs)
• Gen V LT: LT1 (6.2L — C7 Corvette, Camaro SS), LT4 (6.2L supercharged — Z06 Corvette, Camaro ZL1)
• LS swap applications: Any engine swap using a Gen III/IV LS or Gen V LT block with the standard cylinder head bolt pattern — S-chassis, AE86, FC/FD RX-7, E30/E36, 240Z/280Z, and the full spectrum of LS-swapped platforms

Installation Notes

• ARP thread lubricant: Included in the kit. Apply to threads and under the bolt flange before installation. Using ARP’s supplied lubricant is critical — the published torque value for ARP 134-1102 is calibrated for use with ARP Ultra-Torque or equivalent. Using engine oil, anti-seize, or dry installation will result in incorrect clamp load at the specified torque value.
• Torque specification: Follow ARP’s torque specification for this kit (refer to ARP’s instruction sheet included with the kit or ARP’s online torque spec tool). Typical LS header bolt torque with ARP lubricant is in the 25–30 ft-lb range — confirm against the ARP spec sheet for 134-1102.
• Thread preparation: Chase the cylinder head exhaust port threads with the correct 3/8"-16 tap before installation to remove any corrosion, thread sealant residue, or deformation from previous bolt removal. Clean the threads with brake cleaner and blow dry before applying ARP lubricant.

16-piece kit. 3/8"-16 flange hex. Fits all LS and LT V8 cylinder heads. ARP thread lubricant included. Not for use with OEM torque-to-yield spec — torque to ARP’s published specification. Made in USA. 0.7 lbs.

Specifications

• Brand: ARP (Automotive Racing Products)
• Part Number: 134-1102
• Type: Header / exhaust manifold bolt kit
• Thread size: 3/8"-16 UNC
• Head style: Flange hex
• Drive: 9/16" hex socket
• Quantity: 16 bolts
• Lubricant: ARP thread lubricant included
• Application: All GM LS (Gen III/IV) and LT (Gen V) V8 engines
• Country of manufacture: USA
• Weight: 0.7 lbs