poor traction

some control arms and shocks will help.

Make sure that your posi is still functioning properly. Probably needs a rebuild, but an easy way to check is to jack the rear of the car up, put the trans in neutral (block the front wheels), and with someone else holding the wheel on the other side, try to spin the opposite side ahead. If your helper can hold their wheel with little/no effort, your posi clutches are probably toast. When they get really worn, you can turn one wheel ahead, and the opposite wheel will spin in the other direction, just like an open diff.

Drag radials are a pretty easy way to get better traction, but aren't realistic if the car is daily driven, or sees rain on the freeway.