Oldsmobile 350ci specs: 4.057 x 3.385 in (103 x 86 mm) bore and stroke, shared by all 8 versions. Displacement, compression and factory ratings.
| Displacement | 350 ci |
|---|---|
| Cylinders | 8 |
| Bore | 4.057" |
| Stroke | 3.385" |
| Compression | 9.1–22.5:1 |
| Advertised power | 105–325 hp |
| Years | 1968–1984 |
| Cylinder head data | 3 of 8 engines |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| Oldsmobile 350ci · 4.057" × 3.385" · 9.591:1 | 350 ci | 4.057" × 3.385" | 9.591:1 | 140–155 |
| Oldsmobile 350ci (1976) · 170 hp | 350 ci | 4.057" × 3.385" | 9.061:1 | 170 |
| Oldsmobile 350ci · 4.057" × 3.385" · 22.5:1 | 350 ci | 4.057" × 3.385" | 22.5:1 | 105 |
| L65 | 350 ci | 4.057" × 3.385" | — | 240–250 |
| L74 | 350 ci | 4.057" × 3.385" | — | 260–310 |
| 'Ram Rod 350' | 350 ci | 4.057" × 3.385" | — | 325 |
| W-31 | 350 ci | 4.057" × 3.385" | — | 325 |
| L34 | 350 ci | 4.057" × 3.385" | — | 170–180 |
Compression spans 9.061:1 to 22.5:1, so fuel requirements differ meaningfully between members — worth checking before assuming parts interchange.
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.