ARP 434-1202 SS 12pt Header Bolt Kit M8x1.25 3/8 Flange for Chevy LS Gen III/IV

Vehicle Fitment

• Chevrolet Gen III LS Engines: LS1 (4.8L, 5.3L, 5.7L), LS6 (5.7L) - with 3/8" wide header flange
• Chevrolet Gen IV LS Engines: LS2 (6.0L), LS3 (6.2L), LS7 (7.0L), LSX - with 3/8" wide header flange
• Compatible with any vehicle, swap, or build using a Gen III or Gen IV LS engine with a 3/8" header flange

Fitment Notes

• Designed for headers using a 3/8" wide flange - verify your header flange width before ordering
• Thread size is M8 x 1.25 - confirm your header bolt hole thread spec matches before installation
• Anti-seize compound is recommended during installation to prevent galling with stainless fasteners

Features

• Made from premium 300-series stainless steel - rated at 170,000 psi tensile strength, approximately 15% stronger than Grade 8 steel
• Highly resistant to corrosion and extreme heat, making them ideal for long-term exhaust header use
• Compact 12-point head design allows socket access in tight spaces close to header pipes
• Mirror polished finish for a clean, professional appearance under the hood
• Threads rolled after heat treatment for maximum fatigue strength and thread integrity
• Reusable fasteners - will not stretch or deform under rated load like OEM hardware
• Each kit includes the correct quantity of bolts for a complete LS header installation

Specifications

• Part Number: 434-1202
• Material: ARP 300-Series Stainless Steel
• Tensile Strength: 170,000 psi
• Thread Size: M8 x 1.25
• Underhead Length (UHL): 1.181 in. (30mm)
• Head Style: 12-Point
• Wrench Size: 3/8 in.
• Finish: Polished
• Header Flange Width: 3/8 in.
• Quantity: Set of 12
• Weight: 0.60 lbs.

Included Components

• 12x ARP 300-Series Stainless Steel 12-Point Header Bolts (M8 x 1.25 x 30mm UHL)

Product Description

The ARP 434-1202 is a polished stainless steel header bolt kit designed for Chevrolet Gen III and Gen IV LS engines using a 3/8" wide header flange. Factory header bolts are prone to corrosion, heat damage, and loosening over time - this ARP kit replaces them with 300-series stainless bolts rated at 170,000 psi, delivering stronger clamping force and long-term durability in the high-heat environment of an exhaust header. The compact 12-point head makes installation and removal easier in tight quarters around the header tubes.

This kit is a go-to choice for LS swaps, engine builds, and header upgrades across a wide range of applications. With 12 bolts per set and a mirror polished finish, it covers a full header installation while keeping the engine bay looking clean. Anti-seize compound is recommended during installation to prevent galling - a common issue with stainless fasteners under heat.