To get the hood to mount up from the 85/86 clip, you'll have to cut holes in your cab for the hinges. You'll also have to change out all the wiper linkage and stuff.
Would be simpler to get you a 73/74 setup that looks very good. Many think that is the best look for the squares, and I'm one of them.
But, as long as you have the entire front clip from the 85/86, meaning all the sheet metal (fenders and hood and hinges etc) it can be done in a day.