Do yourself a Favor - Get the Schematics.
Not meaning to sound assinine -- but you
need to have both the donor and recipient wiring diagrams. Lay them out side-by-side. Study - compare and contrast the ignition wiring for both vehicles, and you'll probably answer your own question.
There are just too many year/model options for a conversion to arbitrarily say yes, or no, it will, or won't work. Unless someone is lurking that just happens to have done a '93 5.0L swap (outa' whatever), into an '85 B2 2.9L(?)
To effectively do a swap you really need both wiring diagrams. It makes life soooo much less stressed. My first inclination is to tell you that it probably won't work, but without the wiring diagrams - I could be wrong. At the same time, MSD (or any other aftermarket ignition) is not a must.
Here is one place where many go to purchase OEM wiring diagrams.
www.helminc.com