What Mike said CD. But even on the bottom of the stroke of the eccentric there is still some pressure needed to push the pump down to run the bolts up tight.
You can rotate the engine by a ratchet on the crank bolt, by bumping it with the starter, or if it's run in enough and the belts tight, simply by turning the belt/pulley/fan by hand.
Good luck. No matter how you look at it, on most Broncos that's an awkward spot at best.
Paul