Ranger 4.0l OHV engine changed from a 3 wire Cam Sensor to a 2 wire Cam Sensor in '99.
The 4.0l OHV engine was used in Rangers from 1990 to 2000.
In 2001 Ranger got the 4.0l SOHC engine, SOHC engine is not related in anyway to the 4.0l OHV.
So your OHV engine could be a '99 or '00.
The 3 wire sensor and 2 wire sensor are different types of sensors so it is not just a matter of rewiring, you will need to get a 3 wire sensor so your '93 computer will understand the signal.
I think the Cam synchronizer(what the cam sensor sits on) is the same for either 2 or 3 wire so just the sensor can be changed.
But the Cam synchronizer's are known for bad bushings, so you may what to swap out both.
The cam sensor is used to fine tune the fuel injector timing and for advanced spark timing, engine will run without it but MPG and performance will improve with it working.
4.0l OHV engine looks like this: The Ford Ranger 4.0L Engine - The Ranger Station
4.0l SOHC looks like this: How To Replace the Upper and Lower Thermostat Housing on a Ford 4.0L V6 SOHC Engine
This may be helpful down the road if you need parts: http://www.therangerstation.com/tech...0rebuild.shtml
It gives the differences in the 1990 to 2000 4.0l OHV engines