Bore, stroke, displacement and compression for all 8 Buick Small-Block V8 engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 300–350 ci |
|---|---|
| Cylinders | 8 |
| Bore | 3.750–3.800" |
| Stroke | 3.400–3.850" |
| Compression | 8.5–10.3:1 |
| Advertised power | 140–315 hp |
| Years | 1968–1978 |
| Cylinder head data | 2 of 8 engines |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| Buick Small-Block V8 · 3.800" × 3.850" · 9:1 | 350 ci | 3.8" × 3.85" | 9:1 | 230–285 |
| Buick Small-Block V8 · 3.800" × 3.850" · 10.25:1 | 350 ci | 3.8" × 3.85" | 10.25:1 | 280–315 |
| Buick Small-Block V8 · 3.800" × 3.850" · 8.5:1 | 350 ci | 3.8" × 3.85" | 8.5:1 | 150–230 |
| Buick Small-Block V8 · 3.800" × 3.850" | 350 ci | 3.8" × 3.85" | — | 140–165 |
| Buick Small-Block V8 (1971–1974) | 350 ci | 3.8" × 3.85" | — | 150–260 |
| L32 | 350 ci | 3.8" × 3.85" | — | 160 |
| 340 | 340 ci | 3.75" × 3.85" | 10.25:1 | 260 |
| 300 | 300 ci | 3.75" × 3.4" | 9:1 | 210 |
Both bore and stroke vary across the family, so these are separate castings rather than variations on one block.
Compression spans 8.5:1 to 10.25:1, so fuel requirements differ meaningfully between members — worth checking before assuming parts interchange.
1 of 8 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.