Bore, stroke, displacement and compression for all 4 Cadillac Northstar engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 266.7–281 ci |
|---|---|
| Cylinders | 8 |
| Bore | 3.583–3.661" |
| Stroke | 3.307" |
| Compression | 9.0–10.3:1 |
| Advertised power | 275–440 hp |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| LD8 | 281 ci | 3.6614" × 3.3071" | 10:1 | 275 |
| L37 | 281 ci | 3.6614" × 3.3071" | 10.3:1 | 300 |
| Northstar · 3.661" × 3.307" · 10.3:1 | 279 ci | 3.6614" × 3.3071" | 10.3:1 | 275–320 |
| LC3 | 266.7 ci | 3.5827" × 3.3071" | 9:1 | 440 |
Stroke is constant at 3.3071" across the family — the displacement spread comes from bore, so these share a crank and differ in the block.
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.