maybe
Some 91-94s will fit a 31" and some will not. There is no way to know for sure unless you actually mount the tires and check. Personally I got them to fit with very minimal rubbing (minimal = full-lock, backing up, and hitting bump all at same time...). Some others try them and they rub a lot.
If the tire shop wants to sell you tires they will test fit them and let you try them. Some tires even have a 30 day test drive period so if you don't like them you can take them back.
As a side note, what gears do you have? I found that with 3.27s and 31s my already slow Explorer became slower. I'm now running a 3.08 equivalent. Just something to think about.