Tough one. Very tough one. But... I think I'll tell you what you wanna hear and pick Toney by late KO.
Hearns by decision is a possible outcome here. And I say that as a Toney groupie, and out of the Fab 4... Hearns is at the bottom in terms of my fandom.
I'll take Hearns via decision with Toney coming on strong late and threatening a stoppage. Similar to the Nunn fight only Hearns makes it through.