The LC8 engine is a 6.0L Gen. 4 small block engine used in GM trucks and SUVs between 2011 and 2019.
It is unique among the Gen. 3 and Gen. 4 engines in that it’s the only one designed to operate on gasoline and LPG or CNG fuels.
It’s also unique in that it’s the last of the Vortec Gen. 4 engine to be used in vehicles. The engine specs and information listed here is for a stock LC8 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 LC8 engine? Check out LC8 6.0L Engine Upgrade Guide: Expert Advice for LC8 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 guide is specifically about the GM LC8. You can find our other LS engine spec guides and LS-related tech articles here.
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Chevy 6.0L LC8 Engine Specs
LC8 Performance Specifications
| LC8 Engine Ratings | |
|---|---|
| Compression Ratio | 9.7:1 |
| Horsepower Rating | 342-360 hp Gasoline; 282-301 hp CNG; 332 hp LPG |
| Torque Rating | 373-380 ft./lbs. Gasoline; 320-333 ft./lbs. CNG; 370 ft./lbs. LPG |
LC8 Applications
| VIN 8th Digit | Year | Make | Model |
|---|---|---|---|
| B | 2011-19 | Chevy | Express Van LPG (Cargo Cutaway) |
| B | 2011-19 | GMC | Savana Van LPG (Cargo Cutaway) |
| B | 2011-19 | Chevy | Express Van CNG (Cargo Cutaway) |
| B | 2011-19 | GMC | Savana Van CNG (Cargo Cutaway) |
| B | 2011-19 | Chevy | Silverado HD CNG |
| B | 2011-19 | GMC | Sierra HD CNG |
LC8 Engine Blocks
| LC8 Engine Block Specs | |
|---|---|
| Casting Numbers | 12576181 |
| Material | Iron |
| Displacement | 6.0L / 364 c.i.d. |
| Bore Dia. | 4.000 in. |
| Stroke | 3.622 in. |
| Deck Height | 9.240 in. |
| Bore Spacing | 4.400 in. |
| Thrust Bearing Location | #3 Main |
| Main Cap Style | 6-Bolt |
| Main Housing Bore Dia. | 2.751 in. |
| Cam Housing Bore Dia. | Bore 1/5 = 2.346, Bore 2/4 = 2.326, Bore 3 = 2.307 |
| Cam-to-Crank Centerline | 4.914 in. |
LC8 Rotating Assembly
| LC8 Rotating Assembly Specs | |
|---|---|
| Piston Material | Hypereutectic Cast Aluminum Alloy |
| Piston Style | Dished, with valve reliefs |
| Piston Volume | +6.7cc |
| Wrist Pin Dia. | 0.9431 in. (full floating) |
| Connecting Rod Material | Powdered Metal |
| Connecting Rod Style | I-Beam |
| Connecting Rod Length | 6.098 in. |
| Connecting Rod Housing Bore | 2.225 in. |
| Connecting Rod Bolts | M9 x 1 x 43 |
| Connecting Rod Part Number | 12607475 |
| Connecting Rod Casting Number (last 4 digits) | 3847 |
| Crankshaft Material | Cast Iron |
| Crankshaft Casting Number (last 3 digits) | 216 |
| Crankshaft Main Journal | 2.559 in. |
| Crankshaft Rod Journal | 2.100 in. |
| Reluctor Wheel | 58X |
LC8 Cylinder Heads
| LC8 Cylinder Heads Specs | |
|---|---|
| Casting Numbers | 5364, 823 |
| Material | Aluminum |
| Combustion Chamber Volume | 70cc |
| Intake Port Shape | Rectangle |
| Intake Runner Volume | 257cc |
| Exhaust Port Shape | D-Port |
| Exhaust Runner Volume | 87cc |
| Intake Valve Diameter | 2.165 in. |
| Exhaust Valve Diameter | 1.590 in. |
| Cylinder Head Bolt Style | Torque to Yield (TTY) |
| Cylinder Head Bolt Size | (10) M11 x 2 x 100, (5) M8 x 1.25 x 45 |
LC8 Cam Specifications
| LC8 Cam Specs | |
|---|---|
| Duration @ .050 in. (int./exh.) | 198°/208° |
| Valve Lift (int./exh.) | 0.467 in./0.479 in. |
| Lobe Separation | 116° |
| Cam Gear Attachment | 1-Bolt |
| Cam Gear Poles | 4x |
| Active Fuel Management (AFM) | No |
| Variable Valve Timing (VVT) | Yes |
LC8 Valvetrain
| LC8 Valvetrain Specs | |
|---|---|
| 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 | Intake Rocker |
| Valve Spring Style | Beehive |
| Valve Spring Color | Natural |
| Valve Angle | 15 Degrees |
| Intake Valve Material | SIL-1 Nitride Steel (unique alloy to LC8) - Solid Stem |
| Intake Valve Dia. | 2.165 in. |
| Exhaust Valve Material | Inconel Steel (unique alloy to LC8) - Solid Stem |
| Exhaust Valve Dia. | 1.590 in. |
| Valve Seat Material | Brico 3010 (Unique for CNG/LPG durability) |
Other LC8 Specs
| LC8 Throttle Body, Fuel Injectors, Oil Pan Specs & More | |
|---|---|
| Intake Manifold | Truck-Style |
| Throttle Body | 87mm, 4-bolt |
| Throttle Control | Electronic, Drive-by-Wire |
| Fuel Injector Part Number | 12613412 |
| Fuel Injector Flow | 49.2 lbs./hr. @ 58 psi |
| Flex Fuel Capable (E-85) | No |
| Fuel Injector Length (between O-Rings) | 1.771 in. |
| Fuel Injector Connector | EV6-USCAR |
| Computer | E38 |
| Crankshaft Reluctor Ring | 58X |
| Camshaft Sensor Location | Front mount, 4X on cam |
| Oil Pan | Deep Rear Sump |
| Oil Pump | Standard Flow (0.96 c.i. per rev) |
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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.
Great info on the LC8 Brian, thank you. What would be a good choice in after-market rocker arms if I want to keep the 1.7 ratio?