Bore, stroke, displacement and compression for all 3 Pontiac Pontiac 421ci engines. Compare variants side by side.
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| Pontiac 421ci · 4.093" × 4" · 11:1 | 421 ci | 4.093" × 4" | 11:1 | 405 |
| Pontiac 421ci · 4.093" × 4" · 10.75:1 | 421 ci | 4.093" × 4" | 10.75:1 | 350–376 |
| Pontiac 421ci · 4.093" × 4" · 10.5:1 | 421 ci | 4.093" × 4" | 10.5:1 | 320–338 |