8.25 rear....1985 sure grip swap into a 1973 housing?

I'm replacing the 7.25 R-end in my 72 318 Dart. I have a 1973 8.25 A body rear (905) that's open center. I also have a 1985 8.25 from a van (3723599) that is 3.21 sure grip. My plan is to take the 1985 center and stuff it in the 1973 rear that is correct dimensions. Will this work? Will the 1973 axles fit the 1985 SG center? Thanks!