'66 Biscayne- chassis adjustment for better traction-

[Mark Yacavone]

That type suspension is one of the easiest to raise the rear of the uppers on .
You need some flat stock , a few extra short bolts, and a welder..and. oh yes , the ability to use it properly.
I don't think I'd go up 2, 1/2 inches though.
Solid lower bushings help those cars immensely . There is very little binding, with the uppers running straight ahead.