551696 Exhaust Manifold Bolt Kit M8x1.25 12PCS Grade 10.9 for LS | Eliminate ticking & exhaust leaks, Zinc Plated for Anti-Rust, fits Silverado Sierra Tahoe Yukon 4.8/5.3/6.0 LS Vortec Engines

Is That a Tick-Tick-Tick Coming from Your Silverado's Engine Bay?You know the sound. A subtle tick on a cold start that disappears when the engine warms up. It's the classic sign of a failing GM LS exhaust manifold bolt. Over time, extreme heat cycles cause the weak factory bolts to stretch, snap, or back out, creating an exhaust leak that robs power and ruins your weekend plans. Don't let a broken bolt turn a simple repair into a major headache.Built Stronger Than Factory – For Life.We engineer our 551696 exhaust manifold bolts to survive the harshest real-world conditions so you can install them and forget them.Grade 10.9 Alloy Steel: Significantly higher tensile strength than stock hardware; resists stretching and vibration.Premium Zinc Plating: Unlike basic black oxide coatings that wear thin over time, our zinc-plated finish delivers long-lasting corrosion protection against rust, road salt, and moisture. This ensures easy disassembly years later without galling or seized threads.Integrated Flange Head: Eliminates the hassle of separate washers for faster, cleaner installation.8mm Compact Hex Head: Provides perfect clearance for long tube headers and tight bends.Fits All Your GM LS & Vortec Engines.Standard replacement for part number 551696. Compatible with:Chevy Silverado | GMC Sierra | Tahoe | Yukon | Suburban | Avalanche4.8L 5.3L 6.0L | LS1 LS2 LS3 LS6 | LM7 LQ4 LQ9 LY6 L96 Vortec enginesWorks perfectly with GM 12617944 exhaust manifold gasket (gasket sold separately).For Daily Drivers, Heavy Towing, and Weekend LS Swaps.Whether you're fixing a leaky daily driver, finishing a meticulous LS swap into a classic C10, or upgrading to long tube headers for more power, these bolts deliver consistent torque, a perfect seal, and zero headaches.Pro Installation Tips for a Perfect Seal.✅ Always apply high-temp anti-seize compound to bolt threads.✅ Torque to 18–22 ft-lbs using a calibrated torque wrench.✅ Tighten in 2-3 passes starting from the center bolts and spiraling outward.✅ Replace the exhaust manifold gasket at the same time for best results.Your Complete 12-Piece Repair Kit.12x M8x1.25x25mm Grade 10.9 zinc-plated flanged exhaust manifold bolts.100% Fit Guarantee | No Missing Pieces | No Wrong Sizes | No Cheap Substitutes.Click "Add to Cart" now to silence the tick, seal the leak, and drive with confidence.Q&A:Q: Will these exhaust manifold bolts fix the ticking noise on my 5.3L Silverado or Sierra?A: Yes, absolutely. That ticking sound is almost always an exhaust manifold leak caused by a failed or broken factory bolt. Our SANHLSKJ Grade 10.9 bolts provide a permanent, high-strength seal that eliminates the noise and restores quiet engine operation.Q: Do these bolts work with aftermarket long tube headers on an LS3 or LS1?A: Yes, they are an excellent choice for long tube headers. The 8mm compact hex head is specifically designed to provide better socket clearance for the tight bends of aftermarket headers, making installation much easier than with stock bolts.Q: What is the correct torque specification for these exhaust manifold bolts?A: We recommend a final torque of 18-22 ft-lbs. Always use a calibrated torque wrench and tighten in 2-3 passes starting from the center bolts and working outward in a spiral pattern. Be sure to apply a small amount of high-temperature anti-seize to the threads.Q: Is the GM 12617944 exhaust manifold gasket included with this bolt kit?A: No, this kit includes the 12 premium Grade 10.9 bolts only. For a complete, leak-free repair, we highly recommend purchasing a new GM 12617944 exhaust manifold gasket and replacing it at the same time.Q: Do these fit a 6.0L LQ4 engine in a GMC Yukon or Chevrolet Tahoe?A: Yes, these bolts are a direct fit for the 6.0L LQ4 and all other GM LS & Vortec 4.8L, 5.3L, and 6.0L engines. They are manufactured to exact factory specifications for part number 551696.Q: Are these bolts longer or shorter than the stock bolts? Are they exactly the same length?A: These bolts are manufactured to the exact stock length: M8x1.25x25mm. They feature full usable threads and will not bottom out early or leave you with insufficient thread engagement. You can expect a perfect fit.Q: Will these bolts rust or seize in the aluminum cylinder heads over time?A: No. The premium zinc-plated finish provides superior rust resistance compared to standard black oxide coatings on factory bolts. When paired with high-temp anti-seize during installation, they will not gall or seize in the aluminum head, ensuring easy removal years down the road.Q: Do I really need to use anti-seize on these bolts?A: Yes, we strongly recommend it. Using high-temp anti-seize compound on the threads is a critical step to prevent galvanic corrosion between the steel bolt and aluminum cylinder head. This ensures you can easily remove the bolts for future repairs without them snapping off.Q: What kind of coating do these bolts have? Are they black oxide or zinc?A: These bolts feature a premium zinc-plated finish. Compared to basic black oxide coatings that can wear thin over time, zinc plating offers longer-lasting corrosion protection and a cleaner, professional appearance that holds up through repeated heat cycles.

• ✓ FIX EXHAUST LEAKS & TICKING NOISES PERMANENTLY - Upgraded Grade 10.9 alloy steel bolts stop the common GM LS manifold leak, annoying ticking sounds, and gasket blowouts. Restore quiet, efficient engine performance for Silverado, Sierra, Tahoe, and Yukon 4.8L 5.3L 6.0L engines.
• ✓ HEAVY-DUTY 10.9 GRADE WITH ZINC PLATING FOR EXTREME HEAT & RUST RESISTANCE - Forged from high-strength alloy steel with a premium zinc-plated finish, these bolts withstand brutal exhaust heat, constant vibration, and road salt. The zinc coating provides superior corrosion protection compared to standard black oxide finishes—no more snapping, stretching, or seizing.
• ✓ PRECISE JIS FIT FOR LS SWAPS & LONG TUBE HEADERS - These M8x1.25x25mm flanged bolts meet strict JIS specifications with an integrated washer-less head. A direct replacement for part 551696, they fit LS1 LS2 LS3 LS6 LM7 LQ4 LQ9 Vortec engines. The compact 8mm hex head provides maximum socket clearance for tight aftermarket headers.
• ✓ DIY-FRIENDLY INSTALLATION WITH PROFESSIONAL RESULTS - Smooth, clean threads prevent binding and allow easy hand-starting into aluminum cylinder heads. For a lifetime secure seal, we recommend pairing with high-temp anti-seize and torquing to 18-22 ft-lbs in a center-out spiral pattern.
• ✓ 12PCS COMPLETE KIT | FACTORY SPEC | LIFETIME SUPPORT - You receive a full 12-piece set to complete one engine repair. These bolts are manufactured to strict factory dimensions and work seamlessly with the GM 12617944 exhaust manifold gasket. Backed by lifetime support for total peace of mind.