Engine Compression
COMPRESSION SPECIFICATIONS
| Compression Ratio | |||
| 5.0L | |||
| Federal | 9.2:1 | ||
| Calif. | 8.6:1 | ||
| 5.7L | |||
| Light Duty | 8.2:1 | ||
| Heavy Duty | 8.3:1 | ||
| 7.4L | 8.5:1 | ||
| Compression Pressure | 150 psi (10.5 kg/cm2 ) | ||
| Maximum Pressure Variation | 20 psi (1.4 kg/cm2 ) | ||
When making compression checks, disconnect the ignition switch connector pink wire from high energy ignition system. With air cleaner removed and throttle and choke wide open, crank engine through at least four compression strokes.