GMC 376ci specs: 4.065 x 3.622 in (103.3 x 92 mm) bore and stroke, shared by all 4 versions. Displacement, compression and factory ratings, plus rod ratio.
| Displacement | 376 ci |
|---|---|
| Cylinders | 8 |
| Bore | 4.065" |
| Stroke | 3.622" |
| Advertised power | 403–420 hp |
| Years | 2007–2026 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| L92 | 376 ci | 4.065" × 3.622" | — | 403 |
| L9H | 376 ci | 4.065" × 3.622" | — | 403 |
| L86 | 376 ci | 4.065" × 3.622" | — | 420 |
| L87 | 376 ci | 4.065" × 3.622" | — | 420 |
All are oversquare — bore larger than stroke, which favours revs over low-end torque.
Each engine page carries rod ratio, mean piston speed, bore/stroke character and cylinder head specs where published, and links into the calculators with its dimensions already filled in.