What's the rear axle ratio? Assuming it has the final drive in place? Also assuming it's a Ford 9 inch style rear axle.
Also, now's a good time to find your transmission. Hello SUMMIT? Get one that's already rebuilt and has some kind of a warranty. You'll probably never be able to take advantage of a warranty as it'll expire before you get on the road. But for a short time, they'll stand behind it. Also - you'll need to find a flywheel as that 5.0 you have was a manual tranny car judging by the gear hanging on the back.
Also the flywheel bolts and the starter locate plate. Should be able to source one from a local junk yard or U-Pick... Just some thoughts..