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6.2L LS3 V8 · Engine Mechanical

LS3 Engine Mechanical Specifications

The complete spec sheet, organized by assembly: general engine data, then every dimension and tolerance for the block, crankshaft, camshaft, connecting rods, cylinder heads, pistons, rings, lubrication, and valvetrain. Each figure is shown in both of GM's columns, metric and imperial.

Two values on this sheet are printed wrong in the manufacturer's manual. They are flagged below and explained in full on the corrections page.

General

Specification Metric Imperial
Engine Type V8 —
Displacement 6.2L 376 CID
RPO LS3 —
VIN W —
Bore Corrected GM published 4.0065–4.0065 in — corrected here. 103.241–103.259 mm 4.0646–4.0653 in
Stroke 92.0 mm 3.622 in
Compression Ratio 10.7:1 —
Firing Order 1–8–7–2–6–5–4–3 —
Spark Plug Gap 1.02 mm 0.04 in

Block

Specification Metric Imperial
Camshaft Bearing Bore 1 and 5 Diameter 59.58–59.63 mm 2.345–2.347 in
Camshaft Bearing Bore 2 and 4 Diameter 59.08–59.13 mm 2.325–2.327 in
Camshaft Bearing Bore 3 Diameter 58.58–58.63 mm 2.306–2.308 in
Crankshaft Main Bearing Bore Diameter 69.871–69.889 mm 2.75–2.751 in
Crankshaft Main Bearing Bore Out-of-Round 0.006 mm 0.0002 in
Cylinder Bore Diameter 103.241–103.259 mm 4.0646–4.0653 in
Cylinder Head Deck Height – Measuring from the Centerline of Crankshaft to the Deck Face 234.57–234.82 mm 9.235–9.245 in
Cylinder Head Deck Surface Flatness – Measured within a 152.4 mm (6.0 in) Area 0.11 mm 0.004 in
Cylinder Head Deck Surface Flatness – Measuring the Overall Length of the Block Deck 0.22 mm 0.008 in
Valve Lifter Bore Diameter 21.417–21.443 mm 0.843–0.844 in

Camshaft

Specification Metric Imperial
Camshaft End Play 0.025–0.305 mm 0.001–0.012 in
Camshaft Journal Diameter 54.99–55.04 mm 2.164–2.166 in
Camshaft Bearing Diameter 55.063–55.088 mm 2.1678–2.1688 in
Camshaft Journal-to-Bearing Clearance 0.023–0.098 mm 0.0009–0.0038 in
Camshaft Journal Out-of-Round 0.025 mm 0.001 in
Camshaft Lobe Lift – Intake 8.24 mm 0.324 in
Camshaft Lobe Lift – Exhaust 7.77 mm 0.306 in
Camshaft Runout – Measured at the Intermediate Journals 0.05 mm 0.002 in

Connecting Rod

Specification Metric Imperial
Connecting Rod Bearing Clearance – Production 0.023–0.065 mm 0.0009–0.0025 in
Connecting Rod Bearing Clearance – Service 0.023–0.076 mm 0.0009–0.003 in
Connecting Rod Bore Diameter – Bearing End 56.505–56.525 mm 2.224–2.225 in
Connecting Rod Bore Out-of-Round – Bearing End – Production 0.004–0.008 mm 0.00015–0.0003 in
Connecting Rod Bore Out-of-Round – Bearing End – Service 0.004–0.008 mm 0.00015–0.0003 in
Connecting Rod Side Clearance 0.11–0.51 mm 0.00433–0.02 in

Crankshaft

Specification Metric Imperial
Connecting Rod Journal Diameter – Production 53.318–53.338 mm 2.0991–2.0999 in
Connecting Rod Journal Diameter – Service 53.308 mm 2.0987 in
Connecting Rod Journal Out-of-Round – Production 0.005 mm 0.0002 in
Connecting Rod Journal Out-of-Round – Service 0.01 mm 0.0004 in
Connecting Rod Journal Taper – Maximum for 1/2 of Journal Length – Production 0.005 mm 0.0002 in
Connecting Rod Journal Taper – Maximum for 1/2 of Journal Length – Service 0.02 mm 0.00078 in
Crankshaft End Play 0.04–0.2 mm 0.0015–0.0078 in
Crankshaft Main Bearing Clearance – Production 0.02–0.052 mm 0.0008–0.0021 in
Crankshaft Main Bearing Clearance – Service 0.02–0.065 mm 0.0008–0.0025 in
Crankshaft Main Journal Diameter – Production 64.992–65.008 mm 2.558–2.559 in
Crankshaft Main Journal Diameter – Service 64.992 mm 2.558 in
Crankshaft Main Journal Out-of-Round – Production 0.003 mm 0.000118 in
Crankshaft Main Journal Out-of-Round – Service 0.008 mm 0.0003 in
Crankshaft Main Journal Taper – Production 0.01 mm 0.0004 in
Crankshaft Main Journal Taper – Service 0.02 mm 0.00078 in
Crankshaft Rear Flange Runout 0.05 mm 0.002 in
Crankshaft Reluctor Ring Runout – Measured 1.0 mm (0.04 in) Below Tooth Diameter 0.7 mm 0.028 in
Crankshaft Thrust Surface – Production 26.14–26.22 mm 1.029–1.0315 in
Crankshaft Thrust Surface – Service 26.22 mm 1.0315 in
Crankshaft Thrust Surface Runout 0.025 mm 0.001 in

Cylinder Head

Specification Metric Imperial
Cylinder Head Height/Thickness – Measured from the Cylinder Head Deck to the Valve Rocker Arm Cover Seal Surface 120.2 mm 4.732 in
Surface Flatness – Block Deck – Measured within a 152.4 mm (6.0 in) Area 0.08 mm 0.003 in
Surface Flatness – Block Deck – Measuring the Overall Length of the Cylinder Head 0.1 mm 0.004 in
Surface Flatness – Exhaust Manifold Deck 0.13 mm 0.005 in
Surface Flatness – Intake Manifold Deck 0.08 mm 0.0031 in
Valve Guide Installed Height – Measured from the Spring Seat Surface to the Top of the Guide 17.32 mm 0.682 in

Intake Manifold

Specification Metric Imperial
Surface Flatness – Measured at Gasket Sealing Surfaces and Measured Within a 200 mm (7.87 in) Area that Includes 2 Runner Port Openings Corrected GM published 0.118 in — corrected here. 0.3 mm 0.0118 in

Lubrication System

Specification Metric Imperial
Oil Capacity – with Filter 5.7 liters 6.0 quarts
Oil Capacity – without Filter 5.4 liters 5.7 quarts
Oil Pressure – Minimum – Hot 165 kPa at 1,000 engine RPM 241 kPa at 2,000 engine RPM 262 kPa at 3,000 engine RPM 24 psig at 1,000 engine RPM 35 psig at 2,000 engine RPM 38 psig at 3,000 engine RPM

Oil Pan

Specification Metric Imperial
Front Cover Alignment – at Oil Pan Surface 0.0–0.5 mm 0.0–0.02 in
Crankshaft Rear Oil Seal Housing Alignment – at Oil Pan Surface 0.0–0.5 mm 0.0–0.02 in
Oil Pan Alignment – to Rear of Engine Block at Transmission Bell Housing Mounting Surface 0.0–0.1 mm 0.0–0.004 in

Piston Rings

Specification Metric Imperial
Piston Ring End Gap – First Compression Ring – Measured in Cylinder Bore – Production 0.17–0.38 mm 0.0067–0.0150 in
Piston Ring End Gap – First Compression Ring – Measured in Cylinder Bore – Service 0.17–0.44 mm 0.0067–0.0173 in
Piston Ring End Gap – Second Compression Ring – Measured in Cylinder Bore – Production 0.32–0.63 mm 0.0126–0.0248 in
Piston Ring End Gap – Second Compression Ring – Measured in Cylinder Bore – Service 0.32–0.69 mm 0.0126–0.0272 in
Piston Ring End Gap – Oil Control Ring – Measured in Cylinder Bore – Production 0.22–0.79 mm 0.0086–0.0311 in
Piston Ring End Gap – Oil Control Ring – Measured in Cylinder Bore – Service 0.22–0.85 mm 0.0086–0.0335 in
Piston Ring to Groove Clearance – First Compression Ring – Production 0.030–0.083 mm 0.0012–0.0033 in
Piston Ring to Groove Clearance – First Compression Ring – Service 0.030–0.083 mm 0.0012–0.0033 in
Piston Ring to Groove Clearance – Second Compression Ring – Production 0.040–0.083 mm 0.0016–0.0033 in
Piston Ring to Groove Clearance – Second Compression Ring – Service 0.040–0.083 mm 0.0016–0.0033 in
Piston Ring to Groove Clearance – Oil Control Ring – Production 0.013–0.201 mm 0.0005–0.0079 in
Piston Ring to Groove Clearance – Oil Control Ring – Service 0.013–0.201 mm 0.0005–0.0079 in

Pistons and Pins

Specification Metric Imperial
Pin – Piston Pin Clearance to Piston Pin Bore – Production 0.002–0.01 mm 0.00008–0.0004 in
Pin – Piston Pin Clearance to Piston Pin Bore – Service 0.002–0.015 mm 0.00008–0.0006 in
Pin – Piston Pin Diameter 23.952–23.955 mm 0.9430–0.9431 in
Pin – Piston Pin Fit in Connecting Rod Bore – Production 0.007–0.02 mm 0.00027–0.00078 in
Pin – Piston Pin Fit in Connecting Rod Bore – Service 0.007–0.022 mm 0.00027–0.00086 in
Piston – Piston Diameter – Measured Over Skirt Coating 103.258–103.289 mm 4.0653–4.0665 in
Piston – Piston to Bore Clearance – Production −0.048 to +0.001 mm −0.0019 to +0.000 in
Piston – Piston to Bore Clearance – Service Limit with Skirt Coating Worn Off 0.055 mm 0.0022 in

Valve System

Specification Metric Imperial
Valves – Valve Face Angle 45 degrees —
Valves – Valve Face Width 1.25 mm 0.05 in
Valves – Valve Lash Net Lash – No Adjustment —
Valves – Valve Lift – Intake 13.97 mm 0.55 in
Valves – Valve Lift – Exhaust 13.22 mm 0.52 in
Valves – Valve Seat Angle 46 degrees —
Valves – Valve Seat Runout – Production 0.05 mm 0.002 in
Valves – Valve Seat Runout – Service 0.08 mm 0.003 in
Valves – Valve Seat Width – Exhaust 1.78 mm 0.07 in
Valves – Seat Width – Intake 1.02 mm 0.04 in
Valves – Valve Stem Diameter – Production 7.955–7.976 mm 0.313–0.314 in
Valves – Valve Stem Diameter – Service 7.95 mm 0.313 in
Valves – Valve Stem-to-Guide Clearance – Production – Intake 0.025–0.066 mm 0.001–0.0026 in
Valves – Valve Stem-to-Guide Clearance – Service – Intake 0.093 mm 0.0037 in
Valves – Valve Stem-to-Guide Clearance – Production – Exhaust 0.025–0.066 mm 0.001–0.0026 in
Valves – Valve Stem-to-Guide Clearance – Service – Exhaust 0.093 mm 0.0037 in
Rocker Arms – Valve Rocker Arm Ratio 1.70:1 —
Valve Springs – Valve Spring Free Length 52.9 mm 2.08 in
Valve Springs – Valve Spring Installed Height 45.75 mm 1.8 in
Valve Springs – Valve Spring Load – Closed 400 N at 45.75 mm 90 lb at 1.8 in
Valve Springs – Valve Spring Load – Open 1175 N at 33.05 mm 264 lb at 1.30 in
  • Note: For valve stem to guide clearance – valve guide inner diameter measurements must be recorded at a depth of 7 mm (0.26 in) in the valve guide bore.

Sources

  • GM Service Information: Engine Mechanical Specifications (6.2L LS3), Document ID 2055077Captured 2026-06-04

Values are cited as facts. We do not reproduce the manufacturer's prose, table layout, or diagrams.