Top End Gasket Kit - 4.100 inch Bore .040 inch

Features:

• Designed for 6.6L Duramax LB7 engines
• Fits 2001–2004 Silverado and Sierra HD trucks
• Compatible with C4500 and C5500 chassis models
• 4.100 inch bore head gasket sizing
• .040 inch multi-layer steel (MLS) gasket thickness
• High-performance MLS construction for durability
• Ideal for stock and mildly upgraded builds
• Maintains reliable top-end sealing
• Manufactured to order for quality assurance
• Resists blowout under high cylinder pressure
• Perfect for rebuilds or top-end repairs
• Cometic trusted by professional engine builders

Seal Your Build With Confidence Every Time

When you're diving into a top-end rebuild on your 6.6L Duramax LB7, there’s no room for cutting corners. The Cometic PRO3008T Top End Gasket Kit is built to give your engine the solid, long-lasting seal it deserves. Whether you're refreshing a tired workhorse or prepping for a performance upgrade, this kit provides the confidence you need to bolt everything back together and hit the road without worry. Cometic’s multi-layer steel gasket design is trusted in race engines and daily drivers alike, offering reliable sealing even under high-pressure conditions. With a 4.100 inch bore and .040 inch thickness, it’s tailored for precise fitment on your 2001–2004 GM Silverado, Sierra, Kodiak, or Topkick. It’s not just about performance either, this gasket kit is built to withstand the daily abuse of towing, hauling, or heavy-duty use without breaking a sweat. If you're looking for durability you can trust and quality that speaks for itself, this is the top-end kit to get the job done right.

Built To Match OEM Specs And Beat Them

The Cometic PRO3008T Top End Gasket Kit is engineered for precision and longevity in 6.6L LB7 Duramax engines found in 2001–2004 GM HD trucks and chassis cabs. It includes a .040 inch thick head gasket with a 4.100 inch bore, built using a multi-layer steel (MLS) construction that’s known for its strength and ability to maintain an optimal seal under extreme conditions. This design helps reduce the risk of head gasket failure in both stock and mildly modified engines, providing a level of reliability essential for heavy-duty applications. The MLS material offers improved resistance to combustion pressure and thermal cycling compared to standard gaskets. Designed to meet or exceed OEM fitment, this kit supports proper cylinder sealing for vehicles like the Silverado 2500HD, Sierra 3500, and C4500/5500 models. Since these parts are made to order, production typically takes 2 to 3 weeks, ensuring each kit meets high manufacturing standards. It’s a trusted solution for builders looking to restore top-end integrity with components that work just as hard as the trucks they support.

Fits: 2001, 2002, 2003, 2004 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LB7

Notes:

• Designed specifically for 6.6L Duramax LB7 engines
• Fits 2001–2004 Silverado, Sierra, Kodiak, and Topkick
• Head gasket features 4.100 inch bore and .040 inch thickness
• Made from durable multi-layer steel (MLS) material
• Manufactured to order with 2–3 week production time
• Estimated total delivery time is 2–4 weeks
• Ideal for stock or mildly modified diesel applications
• Not a universal gasket kit, verify fitment before purchase
• Provides improved sealing under high cylinder pressures
• Recommended for top-end rebuilds and engine refreshes