I recently built a spare for my 70 Mach 1 and ran into the exact same problem, then I logged on and saw this OLD thread. As far as I can tell, it doesn't matter if the wheel is upside down, or right side up, or if you put the jack under or on top of wheel. The J-hook will still have an extreme angle. Yes, it's better if you put the J-hook through a lug hole, which is what I ended up doing. This just looks like on of those Ford quality control issues that didn't get worked out for a full size spare. Obviously this problem goes away if you have a Space Saver spare.
Anybody disagree with my findings?