flysclean Up-Pipe Bolt Set for 2001–2016 Chevy/GMC 6.6L Duramax — 12 Bolts, Grade 12.9, Black 12-Point

These are a full set of high-strength 12-point up-pipe bolts from Precision Parts designed to replace fragile factory hardware on 2001–2016 6.6L Duramax Chevy Silverado and GMC Sierra trucks.

If you’re removing, replacing, or servicing the up-pipes, turbo, or exhaust manifold on a 6.6L Duramax from 2001–2016, the factory bolts are a known weak point when reused. This Precision Parts kit provides a complete set of 12 premium bolts with a 12-point head profile, black corrosion-resistant finish, and Grade 12.9 strength for a thicker safety margin than typical Grade 8 fasteners. The set covers both up-pipes so you can swap all hardware at once and avoid future breakage or seizing issues.

Why choose Grade 12.9 bolts instead of stock hardware?

Grade 12.9 fasteners are manufactured to a higher tensile strength and hardness than common Grade 8 bolts, reducing the chance of shear or stretch under high heat and vibration. That extra strength matters where bolts secure the turbo and exhaust connection points, which experience thermal cycling and torque stress.

• Stronger tensile rating than stock bolts for improved durability
• 12-point head increases contact area to resist rounding and stripping
• Black coating adds corrosion resistance in harsh under-hood conditions

Will this kit fit my Duramax 6.6L model?

The set is vehicle-specific for GM 6.6L Duramax diesel engines spanning LB7, LLY, LBZ, LMM and LML model years 2001 through 2016. It replaces the up-pipe bolts that secure the exhaust manifold to the turbo assembly on those platforms.

• Compatible with 2001–2004 LB7, 2004.5–2005 LLY models
• Fits 2006–2007 LBZ, 2007.5–2010 LMM, and 2011–2016 LML engines
• Full set of 12 bolts included to replace both up-pipes

How does the 12-point head design help during installation?

The 12-point head offers more surface area contact for a socket compared with standard 6-point heads, reducing the risk of rounding when reinstalling or removing bolts after long service. That benefit is especially useful on components that see repeated heat cycles and can be difficult to access.

• Improved grip in tight access spaces for common mechanics’ tooling
• Lowered chance of rounded heads during removal or retorque operations
• Works well with thin-wall 12-point sockets often used on exhaust hardware

What does the kit include and what warranty is provided?

The package contains a full set of 12 replacement up-pipe bolts specifically sized for both up-pipes and the turbo manifold interface. Precision Parts backs the fit with a 1-year warranty against manufacturing defects for peace of mind when you replace factory hardware.

• Complete set of 12 Grade 12.9 bolts for both up-pipes
• Black coated finish for corrosion resistance
• 1-year limited warranty from Precision Parts

Who is this for: This bolt set is aimed at owners, technicians, and rebuild shops working on 2001–2016 Chevy Silverado and GMC Sierra trucks with the 6.6L Duramax engine who want to avoid the common failure of reused factory up-pipe bolts. If you’re replacing up-pipes, swapping turbos, or doing exhaust manifold work, replacing all twelve bolts with higher-strength hardware is a straightforward preventative upgrade to reduce future breakage and simplify reassembly.