Unless
one of the bolts were broken changing
them was a BS way of attempting to solve your problem.
Visually
inspect the spring. Is there anything broken? If not then a quick fix
for a Vette with a transverse spring which is normally driven with just
one passenger is to turn
the spring around. Put the left side to the right side and right to the
left. This
may buy you a bit of time before the spring will have to be replaced.
If
there are broken leaves or you normally have a passenger, then a new
spring is in your future.