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Plymouth B (1962–1966) specs: 361 ci (5.9L) 8-cylinder, 4.125 x 3.375 in (104.8 x 85.7 mm) bore and stroke. Rated 265-305 hp, 1962–1966.
The Plymouth B (1962–1966) is oversquare — the 4.125" bore exceeds the 3.375" stroke by 22.2% — a layout that favors airflow and RPM over leverage at the crank. The 3.375" stroke does not reach 4,000 ft/min of mean piston speed until about 7,100 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 8 cylinders displaces 45.1 ci (739 cc).
It is one of 27 engines in the B family, sitting between the 350 ci and 400 ci members. 3 factory variants share these dimensions, rated from 265 to 305 hp across 1962–1966.
| Displacement | 361 ci / 5.9 L |
|---|---|
| Bore | 4.125" |
| Stroke | 3.375" |
| Cylinders | 8 |
| Configuration | V8 |
| Bore/stroke ratio | 1.222 |
| Block material | cast iron |
|---|---|
| Head material | cast iron |
| Valvetrain | OHV |
| Fuel type | gas |
| Advertised HP | 265–305 hp |
| Years | 1962–1966 |
| Bore/stroke character | 1.222 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 3,375 ft/min — conservative for a street engine |
| Displacement per cylinder | 45.1 ci |
Each link opens the calculator with this engine's specs already filled in.
These records share identical bore, stroke, displacement and compression. They differ by model year and factory power rating.
| Year | Advertised HP | Code |
|---|---|---|
| 1962 | 305 hp | — |
| 1965 | 265 hp | — |
| 1966 | 265 hp | — |