Vehicle Applications

• 1999–2001 Chevrolet Suburban
• 1999–2004 Chevrolet Silverado 2500
• 2001–2007 Chevrolet Silverado 1500 
• 2001–2007 Chevrolet Silverado 2500 HD
• 2001–2007 Chevrolet Silverado 3500 HD
• 2002–2004 GMC Sierra 1500 Denali
• 2001–2006 GMC Sierra 1500 (2007 Classic)
• 1999–2004 GMC Sierra 2500
• 2001–2006 GMC 2500 Sierra HD (2007 Classic)
• 2001–2006 GMC 3500 Sierra HD (2007 Classic)
• 2001–2006 GMC Yukon Denali, XL1500, XL2500
• 2003–2007 Chevrolet Express
• 2003–2007 GMC Savana
• 2003–2007 Hummer H2

Product Highlights

• Gen III Iron Cylinder Block
• Cathedral Port Aluminum Cylinder Heads
• Drve By Cable (Mechanical Throttle) 1999-2002
• Drive By Wire (Electronic Throttle) *phased in on most 2003+ models
• 24X Ignition Systems

LQ4 Engine Specs (VIN "U")

The information listed here is for the stock engine.

Performance Specifications
Compression Ratio	9.4:1
Horsepower Rating	300-330 hp
Torque Rating	360-370 ft./lbs.

 

Application Information
VIN 8th Digit	Year	Make	Model
U	1999-01	Chevrolet	Suburban
	1999-04		Silverado 2500
	2001-07		Silverado 1500
			Silverado 2500 HD
			Silverado 3500 HD
	2002-04	GMC	Sierra 1500 Denali
	2001-06		Sierra 1500 HD (2007 Classic)
	1999-04		Sierra 2500
	2001-06		Sierra 2500 HD (2007 Classic)
			Sierra 3500 HD (2007 Classic)
			Yukon Denali, XL1500, XL2500
	2003-07	Chevrolet	Express
		GMC	Savana
	2003-07	Hummer	H2

 

Engine Block Specifications
Casting Numbers	12551364, 12573581, 12577184
Material	Iron
Displacement	6.0L / 364 cid
Bore Dia.	4.000 in.
Stroke	3.622 in.
Deck Height	9.230-9.240 in.
Bore Spacing	4.400 in.
Thrust Bearing Location	#3 Main
Main Cap Style	6-Bolt
Main Housing Bore Diameter	2.751 in.
Cam Housing Bore Diameter	Bore 1/5 = 2.326, Bore 2/4 = 2.317, Bore 3 = 2.307 (1999-2003 1st design)
	Bore 1/5 = 2.346, Bore 2/4 = 2.326, Bore 3 = 2.307 (2003- 2007 2nd design)
Cam-to-Crank Centerline	4.914 in.

 

Rotating Assembly Specifications
Piston Material	Hypereutectic Cast Aluminum Alloy
Piston Style	Dished
Piston Volume	+6.7cc
Wrist Pin Dia. (1999-04)	0.9447 in., 0.9448 in. (Pressed)
Wrist Pin Dia. (2005-07)	0.9429 in., 0.9431 in (Full Floating)
Connecting Rod Material	Powdered Metal
Connecting Rod Style	I-Beam
Connecting Rod Length	6.098 in.
Connecting Rod Bolts	M9 x 1 x 43
Crankshaft Material	Cast Iron
Crankshaft Main Journal	2.559 in.
Crankshaft Rod Journal	2.100 in.
Reluctor Wheel	24x
Flexplate/Flywheel Mounting Flange (1999-2000)	1.250 in.
Flexplate/Flywheel Mounting Flange (2001-07)	0.857 in.

 

Cylinder Head Specifications
Years	1999-2000	2001-07
Casting Numbers	373, 873	317, 035
Material	Iron	Aluminum
Combustion Chamber Volume	71cc	71cc
Intake Port Shape	Cathedral	Cathedral
Intake Runner Volume	200cc	210cc
Exhaust Port Shape	Oval	D Port
Exhaust Runner Volume	70cc	75cc
Intake Valve Diameter	2.000 in.	2.000 in.
Exhaust Valve Diameter	1.550 in.	1.550 in.
Cylinder Head Bolt Style	Torque to Yield (TTY)	Torque to Yield (TTY)
Cylinder Head Bolt Size (1999 - 03)	(8) M11 x 2 x 155, (2) M11 x 2 x 100, (5) M8 x 1.25 x 45
Cylinder Head Bolt Size (2004 - 2007)	(10) M11 x 2 x 100, (5) M8 x 1.25 x 45

 

Camshaft Specifications
Years	1999-2000	2001-07
Duration at .050 in (int./exh)	191/190	196/207
Valve Lift (int./exh)	0.457 in./0.466 in.	0.467 in./0.479 in.
Lobe Separation Angle (in degrees)	114	116
Cam Gear Attachment	3-Bolt	3-Bolt

 

Valvetrain Specifications
Lifter Style	Hydraulic Roller
Lifter Link Style	Plastic Lifter Tray
Lifter Body Diameter	0.842 in.
Pushrod Length	7.385 in.
Rocker Arm Mounting Style	Pedestal
Rocker Arm Style	Die-Cast, Roller Fulcrum
Rocker Ratio	1.7
Rocker Offset	None
Valve Spring Style	Beehive
Valve Spring Color	Natural
Valve Angle	15 Degrees
Intake Valve Material	Steel - Solid Stem
Intake Valve Dia.	2.000 in.
Exhaust Valve Material	Steel - Solid Stem
Exhaust Valve Dia.	1.550 in.

 

Other Specifications
Intake Manifold	Truck Style
Throttle Body	80mm, 3-Bolt
Throttle Control	All Cable Operated, 1999-02
	Drive-by-Wire *phased in on most 2003+ models
Fuel Injector Flow	24.8 lb/hr @ 58 psi
Fuel Injector Length (between O-Rings)	1.900 in.
Fuel Injector Connector	Mini-Delphi / Multec2
PCM	Warren
Crankshaft Reluctor Ring	24x
Camshaft Sensor	Rear Mount, 1x on cam
Oil Pan	Deep Rear Sump
Oil Pump	Standard Volume