Buick 455ci specs: 4.313 x 3.90 in (109.6 x 99.1 mm) bore and stroke, shared by all 4 versions. Displacement, compression and factory ratings, plus rod ratio.
| Displacement | 455 ci |
|---|---|
| Cylinders | 8 |
| Bore | 4.313" |
| Stroke | 3.900" |
| Compression | 10.0–10.5:1 |
| Advertised power | 175–370 hp |
| Years | 1970–1976 |
| Cylinder head data | 2 of 4 engines |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| Buick 455ci (1974) | 455 ci | 4.313" × 3.9" | — | — |
| Buick 455ci · 4.313" × 3.9" · 10:1 | 455 ci | 4.313" × 3.9" | 10:1 | 350–370 |
| Buick 455ci · 4.313" × 3.9" · 10.5:1 | 455 ci | 4.313" × 3.9" | 10.5:1 | 175–360 |
| Buick 455ci · 4.313" × 3.9" · 10.28:1 | 455 ci | 4.313" × 3.9" | 10.28:1 | 205 |
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.