Restore your engine's mechanical integrity with this complete pair of all-new 6.6L LML Duramax cylinder heads, specifically engineered for 2011–2016 Chevrolet Silverado and GMC Sierra 2500HD/3500HD applications. These are brand-new castings — not remanufactured — designed to withstand the increased cylinder pressures and thermal loads inherent to the LML platform. Every unit is precision-machined in-house on Rottler equipment, pressure tested to 60 PSI, and vacuum tested port-by-port before leaving our shop.
Unlike "shelf-stock" heads that ship straight from a casting house, every head we sell runs through our complete in-house verification and machining process before it reaches the assembly bench.
Every new casting is chemically cleaned and blown out to remove residual machining oils, metal shavings, and manufacturing debris — keeping your oiling system uncontaminated from first start-up.
All final machine work is done in-house on Rottler equipment — including final guide sizing and precision multi-angle valve seat cutting for perfect geometry and clearances.
We exceed factory pressure testing standards. Every head is verified to 60 PSI to confirm the casting is free of porosity leaks or internal defects that could compromise cooling or oiling systems.
Multi-point inspection of the gasket-sealing surface and bore alignment ensures the head is perfectly flat and within OEM tolerances — critical for proper MLS head gasket sealing.
Valvetrain components are installed and verified in a controlled environment. Spring heights and seal seating are checked to ensure a balanced, performance-ready assembly.
Every intake and exhaust port is vacuum tested to guarantee a 100% airtight seal between valves and seats — ensuring maximum compression and peak performance right out of the box.
Fits all 2011–2016 GM trucks and vans equipped with the 6.6L Turbo Diesel LML engine. Common applications:
Every cylinder head we sell is backed by a full 2-Year Unlimited Mileage Warranty. No mileage caps, no fine-print surprises. If a covered defect arises, we make it right. View full warranty details →
Receive your new heads, compare them to your originals, and complete installation. A pre-paid return label is included in your shipment. Cores must be returned within 30 days of delivery. View core policy →
The 6.6L LML Duramax is a demanding engine that requires precision when it comes to cylinder head replacement. A worn or improperly prepared head leads to repeat head gasket failures, coolant in the combustion chamber, and oil contamination. Our heads are brand-new castings — machined in-house, tested beyond factory standards, and assembled in a controlled environment before they ship.
This pair fits 2011, 2012, 2013, 2014, 2015, and 2016 GM trucks and vans with the LML engine code, including the Chevrolet Silverado 2500HD, Silverado 3500HD, GMC Sierra 2500HD, Sierra 3500HD, Sierra Denali 2500, Sierra Denali 3500, Chevrolet Express 2500/3500 vans, and GMC Savana 2500/3500 vans.
Not sure if this is the right head for your truck? Call us at 727-609-1700, Monday–Friday 8AM–5PM Eastern. We know Duramax — and we'll make sure you get the right part.