Performance Engine Rebuild Re-Ring Kit for Hummer H2 (2003-2009) 5.3L

Heavy-Duty Engine Rebuild Re-Ring Kit for 2003-2009 Hummer H2 (GMT820)

What it Does: The Performance Engine Rebuild Re-Ring Kit restores dynamic cylinder compression and positive fluid containment on the 2003-2009 Hummer H2 equipped with the 5.3L Gen III V8 to eliminate blow-by and oil contamination.

The Stock Hummer H2 Ring Pack and Gasket Degradation

Factory Vortec 5.3L engines endure extreme thermal cycles and severe operational loads, resulting in premature tension loss in factory cast piston rings and micro-fretting across OEM composite head gaskets. Degraded ring tension permits combustion blow-by past the cylinder walls, contaminating the crankcase, causing cylinder bore wash, and precipitating oil burning. Furthermore, aging paper-composite perimeter gaskets and brittle elastomer front/rear main seals harden under operating heat, yielding chronic vacuum leaks, rear main weeping, and low oil pressure at the rod and main journals.

The Engineering Solution

This re-ring service overhaul kit remedies internal engine wear by pairing precision-gapped, wear-resistant steel piston rings with high-tensile Multi-Layer Steel (MLS) head gaskets. Engineered for standard 3.779-inch (bore applications noted up to 4.09-inch max bore sizing) cylinder blocks, the replacement ring pack maintains stable radial wall pressure to maximize dynamic compression sealing. Precision-machined tri-metal main and connecting rod bearings restore hydrodynamic oil clearance to protect the crankshaft journals under high load. High-grade fluoroelastomer crank seals and viton-embossed perimeter covers ensure positive, leak-free oil containment.

What's Included

• 1 Gen III Valley Cover Gasket (12558178)
• 2 LS1/LS2/LS3 Header Gaskets
• 1 LS Oil Pan Gasket
• 2 LS Water Pump Gaskets
• 1 LS Front Cover Gasket
• 2 LS Valve Cover Gaskets
• 1 LS Damper Seal
• 1 LS Rear Cover Gasket
• 1 Rear Main Seal
• 4 Water Crossover/Block Off Gaskets (12551933)
• 1 Oil Filter Adapter Bypass Gasket (12611384)
• 2 Knock Sensor Grommets (12558177)
• 2 Multi-Layer Steel (MLS) Head Gaskets
• 1 Cylinder Head/Engine Bolt Kit
• 1 Complete Piston Ring Set
• 1 Main Bearings & Connecting Rod Bearings Set

Technical Specifications

Compatibility

• 2003-2009 Hummer H2 Base (5.3L OHV V8)
• Direct-fit for 4.8L and 5.3L Gen III small block V8 architectures

Frequently Asked Questions & Fitment Warnings

Does this fit the GMT820 H2?

Yes, this is a direct fit for 2003-2009 Hummer H2 applications equipped with a 5.3L Gen III small-block engine. Piston rings included in this kit will not fit 6.0L or 6.2L engines.

Are intake manifold gaskets included in this overhaul package?

No, intake manifold gaskets are not included and must be sourced separately to complete your top-end assembly.

The Hummer Durability Standard

Engineered to handle severe utility hauling, rocky trails, and high-load towing demands, these premium internal components restore factory cylinder compression and ensure critical oil retention under extreme drivetrain stress.