94 B4000 cam sensor or engine swap???

I have a 1994 B4000 with the 4L V6 engine - same as Ranger or Explorer. It has a cam sensor (aka cylinder identification sensor) on the rear of the engine. I think that sensor has failed but I am not sure (the computer error code says it is bad and the engine runs very roughly). A new one is over $500 and there do not seem to be any used ones anywhere. I hate to spend that if that is not really the problem. Also, it almost looks like the engine must be pulled to even gain access to replace the sensor. The engine has 200,000 miles and surely is tired by now.
So, here is the question. I have a '92 explorer 4L engine with low miles. Is it feasible to swap the engine into the B4000? Will it bolt to the manual 5sp tranny? Will the wiring harness match up? Motor mounts? etc? What other issues will I face?
Thanks
Alan