Buick GM Buick Nailhead 401, Engine
| Engine capacity | 6,572 cm³ |
| Maximum power (range), hp | 265 - 325 |
| Maximum torque, N*m (kg*m) at rpm. | 559 (57) / 2400 |
| Fuel used | Petrol |
| Fuel consumption, l/100 km | 21.8 - 25.4 |
| Engine type | V-shaped, 8-cylinder |
| Additional engine information | Carter ABF 4-barrel carburetor |
| Maximum power, hp (kW) at rpm | 265 (195) / 4400 |
| Compression Ratio (Range) | 8.75 - 10.25 |
| Cylinder diameter (range), mm | 106.36 |
| Piston stroke (range), mm | 92.46 |
| Cooling system (range), l | 17.5 |
| Engine lubrication system (range), l | 3.8 |
| Valve drive | OHV |
| Number of valves per cylinder (range) | 2 |