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The same engine also has a main page: Chevrolet LC3.
GMC LC3 specs: 229 ci (3.8L) 6-cylinder, 3.736 x 3.484 in (94.9 x 88.5 mm) bore and stroke, 8.6:1 compression. Built 1981–1984. Used in the Chevrolet Camaro.
The GMC 229ci (LC3) is oversquare — the 3.736" bore exceeds the 3.484" stroke by 7.2% — a layout that favors airflow and RPM over leverage at the crank. The 3.484" stroke puts mean piston speed at 4,000 ft/min around 6,900 RPM, which is where a production bottom end is generally considered at its limit. A rod ratio of 1.636 is in the range most production engines fall in. Each of the 6 cylinders displaces 38.2 ci (625 cc).
8.6:1 is low by modern standards and generally happy on regular pump fuel.
3 factory variants share these dimensions across 1981–1984.
| Displacement | 229 ci / 3.8 L |
|---|---|
| Bore | 3.736" |
| Stroke | 3.484" |
| Cylinders | 6 |
| Configuration | V6 |
| Compression ratio | 8.6:1 |
| Rod length | 5.7" |
| Rod ratio | 1.636 |
| Bore/stroke ratio | 1.072 |
| Fuel type | gas |
|---|---|
| Years | 1981–1984 |
| Bore/stroke character | 1.072 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 3,484 ft/min — conservative for a street engine |
| Rod ratio | 1.636 — moderate — the range most production V8s fall in |
| Displacement per cylinder | 38.2 ci |
| Static compression | 8.6:1 — low by modern standards, generally happy on regular pump fuel |
Each link opens the calculator with this engine's specs already filled in.
These records share identical bore, stroke, displacement and compression. They differ by model year and factory power rating.
| Year | Advertised HP | Code |
|---|---|---|
| 1981 | — | LC3 |
| 1983 | — | LC3 |
| 1984 | — | LC3 |
8 factory vehicles, 1980–1984. Each year opens that model's engine table.