Bore, stroke, displacement and compression for all 3 Ram B engines, compared side by side. Plus rod ratio and head specs where published.
| Displacement | 383–400 ci |
|---|---|
| Cylinders | 8 |
| Bore | 4.252–4.339" |
| Stroke | 3.374" |
| Compression | 8.2–9.2:1 |
| Advertised power | 200–258 hp |
| Years | 1974 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| 400 B V8 | 400 ci | 4.3386" × 3.374" | 8.2:1 | 200 |
| B 400 | 400 ci | 4.3386" × 3.374" | — | — |
| 383 B V8 | 383 ci | 4.252" × 3.374" | 9.2:1 | 258 |
Stroke is constant at 3.374" 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.