400 Compression Calculator
Simply fill in the form below to calculate your compression ratio.
400 Block — Displacement Reference
| Over | Bore | 3.75" stroke | 4.00" stroke | 4.21" stroke | 4.25" stroke | 4.50" stroke |
|---|---|---|---|---|---|---|
| Stock | 4.120 | 400 | 427 | 449 | 453 | 480 |
| +.030 | 4.150 | 406 | 433 | 456 | 460 | 487 |
| +.035 | 4.155 | 407 | 434 | 457 | 461 | 488 |
| +.040 | 4.160 | 408 | 435 | 458 | 462 | 489 |
| +.060 | 4.180 | 412 | 439 | 462 | 467 | 494 |
| +.065 | 4.185 | 413 | 440 | 463 | 468 | 495 |