Short answer, yes. You don't tighten the end bolts until the spring is back in, and the weight is on the suspension. The resistance of the rubber in the bushing is part of the suspension. Unless you're a really big guy, you can't move them. Once bolted in, you should be able to move them enough to put the spindle/ball joint together.
Most cars or this era work that way. After its all back together, tighten the end bolts in both the upper and lower arms, with the weight on them. I learned that the hard way.
I'm not sure I've said that very well, but it's how it works.