Re: 5.0 Engine swaps
I think you are going to be ok for that sort of swap. Explorer 5.0 blocks are a bit different, and non-fuel injected blocks likewise, but for your purposes there shouldn't be any difference as far as bolt patterns or sensor ports. Furthermore, unlike chevy and B.O.P. (buick, olds, pontiac) mercury and Lincoln don't make different bell housing patterns from the fords; so again you should be in the green. That is until you start spending money to complete this project.
I would encourage you to spend a little extra time and money to put some performance into the motor once you have it stripped down to the short block. Rebuild it, maybe even put a stroker crank into it.
Keep us posted on this one. I for one would like to know how this turns out.