Cylinder Head for GMC Chevrolet Duramax LLY LBZ 6.6L Turbo Diesel 97779579 98025702

Numéro de produit

ML N°	N° OEM	RÉF. N°
MLG064A	97779579
MLG064B	98025702

Informations sur le produit Culasse

1. Présentation du produit

Le LLY (2004.5–2005) et LBZ (2006–2007) are both 6.6L V8 turbocharged diesel engines from GM’s Duramax family, mettant en vedette cast aluminum cylinder heads, 32-valve DOHC valvetrain, et injection directe à rampe commune. They are known for strong towing performance, efficiency, and mechanical durability.

Both engines use similar cylinder heads with minor differences in coolant port designs and emissions sensor locations, making replacement heads mostly interchangeable with small modifications.

2. Spécifications techniques

Article	LLY / LBZ
Cylindrée du moteur	6.6L (6599 cc)
Type de moteur	V8, 90°
Matériau de la culasse	Fonte d'aluminium
Train de soupapes	DOHC, 32-Valve (4 valves per cylinder)
Aspiration	Turbocharged with intercooler
Système de carburant	High-pressure common rail (Bosch)
boulons de culasse	18 per head (torque-to-yield)
Refroidissement	Refroidi par eau
Turbo Type	Variable Geometry Turbo (VGT)
Émissions	LLY: no DPF, LBZ: pre-DPF (no SCR/DEF yet)

3. OEM & Reference Part Numbers

Moteur	OEM Cylinder Head Number
LLY	98055650 / 98055651 (L/R)
LBZ	98060819 / 98060820 (L/R)
Casting Codes	97229810, 97229808, 98060819, 98055650

Both LLY and LBZ heads can be used interchangeably with slight port gasket differences.

4. Véhicules compatibles

Faire	Modèle	Années	Moteur
Chevrolet	Silverado 2500HD / 3500	2004.5–2007	LLY / LBZ
GMC	Sierra 2500HD / 3500	2004.5–2007	LLY / LBZ
Chevrolet	Express Van 2500 / 3500	2006–2007	LBZ
GMC	Savana Van 2500 / 3500	2006–2007	LBZ
Chevrolet / GMC	Kodiak / Topkick C4500+	Some variants	LLY / LBZ

5. Options du produit

Taper	Description
Culasse nue	Casting only – no valves or cams
Loaded Head	Includes valves, valve guides, seals, retainers, keepers
Complete Assembled Head	Fully built with valves, springs, camshafts, injectors seats (if needed)

High-strength cast aluminum
Pressure tested to 150 psi
CNC-machined deck surface and cam journals
Compatible with OEM rocker assemblies and head gaskets

6. Notes d'installation

Utiliser new torque-to-yield (TTY) head bolts ou ARP studs
Suivre GM torque sequence: multiple stage torque-angle procedure
Clean all bolt threads and apply GM-recommended sealant/oil
Remplacer head gasket with high-quality MLS type (Mahle, Victor Reinz)
Verify injector cup sealing (LLY/LBZ use pressed-in injector cups)
Prime oil system before first start and check coolant pressure

7. Common Cylinder Head Issues & Repair Advice

Problème	Symptoms	Cause	Solution recommandée
Cracked Cylinder Head	Coolant in oil, white smoke	Overheat or poor casting	Replace head, inspect for coolant cross-leak
Warped Deck Surface	Joint de culasse soufflé	Overheating or improper torque	Resurface and use upgraded head gaskets
Injector Cup Leak	Coolant in cylinder, misfire	Failed cup seal	Replace cups and reseal with Loctite or equivalent
Coolant Cross-Contamination	Random misfire, pressurized coolant	Casting porosity or warp	Remplacer la tête, le bloc de test de pression
Valve Seat Erosion	Power loss, compression drop	Poor fuel or overheat	Replace seat or full valve job

8. Export & Service Markets

USA & Canada: Primary market (HD trucks, vans)
Mexico / Central America: Exported HD pickups
Afrique: Towing fleet & rebuilt engine market
Moyen-Orient: Used HD fleet and custom vehicle platforms
Australie / Nouvelle-Zélande: LHD-to-RHD converted Dually trucks
Amérique du Sud: Custom diesel conversion market

Déplacement	Carburant	Cylindre	Vallée	Arbre à cames	Année
6.6L	Essence	4	16	1	2004-

Culasse pour GMC Chevrolet Duramax LLY LBZ 6.6L Turbo Diesel 97779579 98025702

Moteur applicable :

Marque applicable :

Voiture applicable :

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Introduction