When I was doing a lot of shocks I ran across a lot of broken crap. Holding a nut on top was too difficult, so I would drop a bolt down from the inside using some curved needlenose or finger finesse, and then put a lockwasher and nut on the bottom, holding the top of the bolt still with a finger. O'course, air tools makes everything easier
The last time I did my springs, I had the bushing side of the lower arm loose, and I was able to spin the spring until it fit into place in the top. I could see the hole from the top, but it didn't look fun. That nail sounds like a good idea.
It has to be lined up in the top, not the bottom, or it will not sit right. Most other GM cars line up at the bottom, and the top pocket is not shaped like ours.
On other cars, the control arm is formed to fit the spring exactly. On ours, the frame is, and the lower arm just has a general pocket, with no sharp formation.
