Fleece Factory LML Duramax Cylinder Head, Passenger | 2011-2016 Silverado/Sierra 2500/3500

Fleece Factory LML Duramax Cylinder Head – Passenger Side | 2011‑2016 Silverado/Sierra 2500/3500

Restore compression, stop coolant loss, and add peace of mind with Fleece’s Freedom Series passenger‑side cylinder head for the 6.6 L LML Duramax. Machined and assembled in Fleece’s Freedom Racing Engine facility, every head is cleaned, decked, pressure‑ and leak‑tested, and fitted with all‑new guides, seals, and springs-ready to bolt on with no core charge.

Key Features

• New bronze valve guides, OE‑rate springs, and Viton® valve‑stem seals pre‑installed.
• Precision‑ground stock valves with a 45° seat and multi‑angle valve job for optimal flow.
• Deck surface milled to < 0.002″ flatness-seals MLS gaskets reliably.
• Pressure & leak tested at 60 psi to verify coolant‑side integrity.
• Sold outright-keep your original head; no core return required.
• Backed by Fleece’s 1‑year limited parts warranty.

What’s Included

• Fully assembled passenger‑side cylinder head (ready to install)
• Factory‑style injector cups installed
• Comprehensive installation guide

Vehicle Fitment

Direct replacement for 2011‑2016 GM Silverado & Sierra 2500/3500 HD 6.6 L LML Duramax in all trims (WT, LT, LTZ, High Country, SLE, SLT, Denali, etc.). Fits 2WD and 4WD models.

Technical Specs

Recommended Companion Parts

• FPE‑61‑10004‑D – Driver‑Side Freedom Series head to freshen both banks.
• GM 12637788 – Grade C MLS head gasket (right/passenger).
• GM 12637785 – Grade C MLS head gasket (left/driver).
• ARP 230‑4201 – ARP 2000 head‑stud kit for 200 k psi clamping force.
• FPE‑34563 / FPE‑34564 – PowerFlo in‑tank lift pumps (short‑/long‑bed) to stabilize rail pressure after a top‑end refresh.

Installation Notes

Pair with new Grade C MLS gaskets and ARP head studs for best sealing. Always chase head‑bolt threads and verify flatness of the engine deck before installation. Torque in three steps following GM’s factory pattern; final torque varies with fastener type (stock bolts vs ARP studs).