[Chipper Chapman]

"Will, only problem I see with solid lowers is you can't pull the lower ball joint forward to gain positive caster..You'll have to do it all on the top.
Just hope that both side "center" in the same place.
You really want a ball type pivot on the bottom with a strut rod type suspension.
Take a look at some of the stuff for early Mustangs or Chevy II's"

Doesn't apply to the chevelle. They use a conventional lower a-arm, no strut rod. You could get tricky and offset the center bore of the bushing if need be however.