Easiest way.

Take off your dist. cap, and turn the crank by hand so the rotor points straight up. Then loosen and pull the dist.

Insert new dist. to where the rotor will point straight up, (with a little adjustment around the mounting bolt), and tighten 'er down. Your timing will remain the same.

85 4Runner - With NEW Marlin 4.7 Gears!! It's a whole new beast!