The L59 engine is a 5.3L Gen. III iron-block engine used in GM trucks and SUVs between 2002 and 2007. It is essentially the flex-fuel version of the LM7

For marketing purposes, it was also known as the Vortec 5300. The engine specs and information listed here is for a stock L59 engine.

Mechanically similar, General Motors’ LS and LS-based Vortec engines wound up on almost every branch of the GM family tree: Chevy, Pontiac, GMC, Cadillac, Buick—heck, even Saab, Hummer, and Isuzu got some LS love.

Since LS and Vortec engines are so common, they’ve become the go-to performance and swap engines of the modern era.

These motors are capable of making a lot of horsepower, and respond well to upgrades like turbos, superchargers, high-flow cylinder heads, intake systems, cams, and nitrous oxide.

[Looking to upgrade your L59 engine? Check out L59 5.3L Engine Upgrade Guide: Expert Advice for L59 Mods to Maximize Performance.]

The aftermarket is strong, crate engines are available, and used motors are often cheaply sourced through junkyards.

Summit Racing has created a series of comprehensive guides for each engine in the LS family, so engine builders and tuners can have a handy reference for their projects.

This specific guide is for the GM L59 5.3L Vortec 5300.

You can find more LS engine spec guides and LS-related information here.

(Summit Racing’s Paul Spurlock and Brian Nutter contributed to this article.)

L59 5.3L Vortec 5300 Engine Specs

L59 Performance Specifications

Engine Ratings
Compression Ratio9.5:1
Horsepower Rating285-295 hp
Torque Rating320-335 ft./lbs.

L59 Applications

VIN 8th DigitYearMakeModel
Z2002-06ChevroletSuburban 1500
Z2002-06GMCYukon XL 1500
Z2002-07ChevroletAvalanche Z71
Z2002-07ChevroletSilverado 1500
Z2002-07GMCSierra 1500

L59 Engine Blocks

L59 Engine Block Specs
Casting Numbers12567392, 12567393, 12551358
Displacement5.3L / 325 c.i.d.
Bore Dia. 3.780 in.
Stroke3.622 in.
Deck Height9.230-9.240 in.
Bore Spacing4.400 in.
Thrust Bearing Location#3 Main
Main Cap Style6-Bolt
Main Housing Bore Dia.2.751 in.
Cam Housing Bore Dia.Bore 1/5 = 2.326, Bore 2/4 = 2.317, Bore 3 = 2.307 (1999-2003)
Cam Housing Bore Dia.Bore 1/5 = 2.346, Bore 2/4 = 2.326, Bore 3 = 2.307 (2003-2007)
Cam-to-Crank Centerline4.914 in.

L59 Rotating Assembly

L59 Rotating Assembly Specs
Piston MaterialHypereutectic Cast Aluminum Alloy
Piston StyleDished
Piston Volume+8cc
Wrist Pin Dia. (2002-04)0.9447 in., 0.9448 in. (pressed)
Wrist Pin Dia. (2005-07)0.9429 in., 0.9431 in. (floating)
Connecting Rod MaterialPowdered Metal
Connecting Rod StyleI-Beam
Connecting Rod Length6.098 in.
Connecting Rod Housing Bore2.225 in.
Connecting Rod BoltsM9 x 1 x 43
Connecting Rod Casting Number (last 3 digits)143
Crankshaft MaterialCast Iron
Crankshaft Main Journal2.559 in.
Crankshaft Rod Journal2.100 in.
Reluctor Wheel24x

L59 Cylinder Heads

L59 Cylinder Head Specs
Casting Numbers862, 706
Combustion Chamber Volume61cc
Intake Port ShapeCathedral
Intake Runner Volume200cc
Exhaust Port ShapeOval
Exhaust Runner Volume70cc
Intake Valve Diameter1.890 in.
Exhaust Valve Diameter1.550 in.
Cylinder Head Bolt StyleTorque to Yield (TTY)
Cylinder Head Bolt Size (2002-03)(8) M11 x 2 x 155, (5) M8 x 1.25 x 45
Cylinder Head Bolt Size (2004-07)(10) M11 x 2 x 100, (5) M8 x 1.25 x 45

L59 Camshaft Specifications

L59 Camshaft Specifications
Duration @ .050 in. (int./exh.)191°/190°
Valve Lift (int./exh.)0.457 in./0.466 in.
Lobe Separation114°
Cam Gear Attachment3-Bolt

L59 Valvetrain

L59 Valvetrain Specs
Lifter StyleHydraulic Roller
Lifter Link StylePlastic Lifter Tray
Lifter Body Diameter0.842 in.
Pushrod Length7.385 in.
Rocker Arm Mounting StylePedestal
Rocker Arm StyleDie-Cast, Roller Fulcrum
Rocker Ratio1.7
Rocker OffsetNone
Valve Spring StyleBeehive
Valve Spring ColorNatural
Valve Angle15 Degrees
Intake Valve MaterialSteel - Solid Stem
Intake Valve Dia.1.890 in.
Exhaust Valve MaterialSteel - Solid Stem
Exhaust Valve Dia.1.550 in.

Other Key L59 Specs

Throttle Body, Fuel Injectors, Oil Pan Specs & More
Intake ManifoldTruck-Style
Throttle ControlElectronic (Drive-by-Wire), except some 2002 models without traction control
Fuel Injector Flow33 lb./hr. @ 50 psi, Return-Style (2002-04)
Fuel Injector Flow36.6 lb./hr. @ 58 psi, Returnless (2005-07)
Fuel Injector Length (between O-Rings)2.5 in.
Fuel Injector ConnectorMini-Delphi / Multec2
Fuel RailPlastic (2002-03), Stainless Steel (2004-07)
Crankshaft Reluctor Ring24x
Camshaft Sensor LocationRear mount, 1x on camshaft
Oil PanDeep rear sump
Oil PumpStandard volume

NOTE: You can find engine specs and detailed engine upgrade advice for every LS and LS-based Vortec truck engine in one place: The Definitive Guide to LS Engine Specs and LS Engine Upgrades.