The Willys F-head four is buried under a doghouse in the cab. The standard compression ratio (CR) was 6.9:1, but a high-compression 7.4:1 head was optional at no cost from the factory. The high-CR engine was for high altitudes but offered a little extra power at sea level. In this era, Jeep often advertised the engine at 75 hp, but that was for the high-compression engine, not the low one. Later, 72 hp was the advertised rating and that was about the difference between the two ratios. Net power (the way we commonly rate power today) was 62 hp and net torque was 111 lb-ft for the low-compression engine.