If you can figure out how to mount the tank where the spare tire carrier is - between the frame rails behind the rear axle - and move the fuel tank door. That's about the only way I know to use a Bronco II fuel tank in a Ranger. Did you read the page I linked above regarding the Duraspark conversion? Here it is again:

The Ford Ranger/Bronco II 2.8L Duraspark Ignition Conversion

I believe the connectors you need are still present on the 2nd gen Rangers. I know for sure that they are installed on my '87 Bronco II. You can also Google "Duraspark Conversion Ford Ranger Bronco II" and probably pull several links to write-ups and discussions on it.

 

There must be a limiting factor to the rear tank size on the Ranger P/U, I have a dual tank Ranger and the rear tank is only 12 gal. The Bronco II body must sit higher allowing the 23 gal tank enough room.........just thinking aloud.

 

That wouldn't surprise me, Old93! I guess it'd be easier to look at making the stock tank work. Easiest way I know of would be to swap the in-tank pump from a high- to a low-pressure tank.