I did mine differently. I used a toolthat tightens the body. Forget the name.
Then installed the trunk braces.Never had a piller crack,ran street radials.Felt
tighter.
Also front braces helped a little. Got them at GM for monte Carlos. Not a big help. As this car which was stolen, had 30,000 miles on it. Had changed the shocks. and put the body bushings in. They helped greatly I felt.
Now Iam building a Limited. Bought the whole PST hader than rubber set,with KYB shocks as a package. This car had 153,000 miles on it a woman drove her kids to school.
All I can say is the car rides and handles better,than my 3,630 ORG GN.
I also added body bushings.Doesn't walk on bumps.It was a bit high in price.
But I love just driving it. Now for amotor. In my life I hope. New paint,Eric's trans, sitting waiting , champion heads sitting. for $ for a motor.......Life you have to roll with it......Lost a motor I was going to purchase.........HTH'ed...Rob