* OHV vs. SOHC: The biggest difference was the valve train. Some 1997 F-150s used a pushrod OHV (Overhead Valve) 4.6L, while others featured a more advanced SOHC (Single Overhead Cam) 4.6L. The SOHC offered improvements in power and fuel economy compared to the OHV. Identifying which you have is crucial for parts compatibility.
* Power Output: Even within OHV and SOHC categories, there were slight variations in horsepower and torque ratings depending on the specific calibration and intended application (e.g., different transmissions, axle ratios). These differences were often subtle, but they existed.
* Internal Components: While sharing the basic modular design, subtle differences might exist in internal components like pistons, connecting rods, or camshafts based on engineering refinements or variations aimed at specific performance goals. These were usually not visually apparent.
* Emissions Equipment: Emissions systems could vary slightly based on federal or state regulations. This could involve differences in catalytic converters, oxygen sensors, or other emission control devices.
In short, simply stating "4.6L engine" for a 1997 F-150 is insufficient for accurate identification. To pinpoint the specific engine variant, you'll need to check the engine code stamped on the engine itself (usually found on a pad near the distributor or on the valve cover) or consult the vehicle's original documentation or a Ford parts catalog using the Vehicle Identification Number (VIN).
