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Ford C/J-code with Drag Pack specs: 429 ci (7.0L) 8-cylinder, 4.362 x 3.59 in (110.8 x 91.2 mm) bore and stroke, 10.5:1 compression. Rated 375 hp, 1970. OHV.
The Ford C/J-code with Drag Pack is oversquare — the 4.362" bore exceeds the 3.59" stroke by 21.5% — a layout that favors airflow and RPM over leverage at the crank. The 3.59" stroke puts mean piston speed at 4,000 ft/min around 6,700 RPM, which is where a production bottom end is generally considered at its limit. A rod ratio of 1.84 is long by production standards — less side-load on the cylinder wall and gentler piston acceleration around TDC, the geometry that tolerates high RPM. Each of the 8 cylinders displaces 53.6 ci (879 cc).
10.5:1 on iron heads is in the range that usually runs on pump premium; iron holds heat, so treat it as the less forgiving side of that range.
It is one of 15 engines in the Ford 429ci family, all of them 429 ci — the differences between them are in compression, heads and rating, not displacement.
| Displacement | 429 ci / 7 L |
|---|---|
| Bore | 4.362" |
| Stroke | 3.59" |
| Cylinders | 8 |
| Configuration | V8 |
| Compression ratio | 10.5:1 |
| Rod length | 6.605" |
| Rod ratio | 1.84 |
| Bore/stroke ratio | 1.215 |
| Block material | cast iron |
|---|---|
| Head material | cast iron |
| Valvetrain | OHV |
| Fuel type | gas |
| Firing order | 1-5-4-2-6-3-7-8 |
| Advertised HP | 375 hp |
| Years | 1970 |
| Year | Version | HP @ rpm | Torque @ rpm | Comp. |
|---|---|---|---|---|
| 1970 | gross | 375 @ 5200 | 450 lb-ft @ 3400 | 10.5:1 |
Factory specification sheet.
| Bore/stroke character | 1.215 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 3,590 ft/min — in the range typical of performance street engines |
| Rod ratio | 1.84 — long — less side loading on the cylinder wall, favours high RPM |
| Displacement per cylinder | 53.6 ci |
| Static compression | 10.5:1 — in the range that usually runs on pump premium |
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