Sorello 2 PCS MLS Exhaust Header Manifold Gasket with Bolts

The Sorello 2 PCS MLS exhaust header manifold gasket kit (part 12617944) is a direct-fit multi-layer steel gasket set with 12 bolts that seals the header to the cylinder head and prevents exhaust leaks.

Engineered to match original equipment dimensions, this Sorello kit replaces worn or leaking header gaskets on a wide range of GM vehicles. The multi-layer steel (MLS) construction withstands high combustion temperatures and maintains a tight seal under thermal cycling. The package includes two gaskets and a full complement of 12 bolts to simplify installation and reduce the need to hunt for fasteners during a repair.

Which vehicles will this gasket kit fit?

This gasket set is manufactured to fit multiple General Motors models that use part numbers equivalent to OE 12617944 and its cross-references. It covers many Cadillac, Chevrolet, GMC, Pontiac, and related variants — particularly V8 applications where header-to-head sealing is required.

• Cadillac CTS, Escalade EXT, Escalade ESV
• Chevrolet Avalanche, Camaro, Corvette, Silverado, Suburban, Tahoe, Impala, Express
• GMC Sierra, Yukon, Envoy, Canyon and related models
• Pontiac Firebird, G8, GTO and similar platforms

How does the MLS construction improve performance?

Multi-layer steel gaskets provide durability and consistent sealing across the flange faces, especially where temperatures and pressure fluctuate. The layered design resists warping, reduces the chance of exhaust leaks, and helps maintain proper backpressure for stable engine operation.

• Resistant to high combustion temperatures
• Better clamp-load retention than single-layer gaskets
• Reduced risk of exhaust manifold leakage and related noise

What comes in the box and what tools or prep are needed?

The kit ships with two MLS header gaskets and twelve OE-equivalent bolts (OE 551696). Prepare basic hand tools, a torque wrench, and surface-cleaning supplies to ensure a flat, clean flange for installation. No modifications are necessary when matching an OE-style replacement.

• 2x multi-layer steel header gaskets
• 12x bolts sized to OE specifications
• Recommended: gasket scraper, brake cleaner, torque wrench

How difficult is installation for a DIYer?

The gasket is manufactured to original dimensions for straightforward swapping, so competent DIYers can complete this repair in a home garage. Follow vehicle-specific torque sequences and inspect flange surfaces; professional installation is recommended if warped surfaces or damaged studs are present.

• Direct-fit design eliminates trimming or modification
• Typical install time depends on access and model — expect 1–3 hours
• Replace damaged studs or clean flanges for best results

Who this is for: This Sorello MLS header gasket kit is aimed at DIY mechanics and professional technicians maintaining GM V8 engines that require OE-equivalent header seals. Choose this kit if you need a durable, direct-replacement gasket with the necessary bolts included to restore a leak-free exhaust seal and avoid exhaust noise, odor, or performance issues commonly caused by failing manifold gaskets.