93 Ford explorer 4.0 ohv into a 2000 ranger 4.0 ohv

No it would not. The '93 engine is controlled by an OBD1 computer and the '00 is controlled by a OBDII computer. Not compatible.

What if I just use the long block from the 93 and all the sensors and manifolds from the 2000?

That is possible, All you have to do if you have both engines sitting there side by side is to compare them for bolt hole locations especially on the front of the motor, and whats attached on the side of the blocks, like the knock sensor. You need a the knock sensor. And would have to take particular attention to the inside of the engines in the valley, I just haven't done a Ford before,

I pushed the 4x4 high and now it won't go back to 4x4 auto.

Yes it does work complete first pull the dash complete with all electronics and behind the driver seat. Wiring harness is needed to corospond the old school obd. I have an 88 ranger with a 94 explorer limited 4.0 and a 84strait 5 speed 410 gears.