Troy
These are 69 Camaro, I would think 5 leaf Nova is the same. Use these type clamps.
http://www.heartbeatcitycamaro.com/store...-kit-1968-1969/
There is no spacer in the center where the bolt is. I have had good luck peening the rivets with a ball peen hammer with the head backed up on something like a heavy vice. I have a section of rail track this works well. Tried an air hammer and it does not get them tight enough.