There is a lot of old/likely missing rubber between you and the road. Upper/lower control arm bushings, the rag joint in the lower steering shaft and the lack of lower body mounts (many G-bodies just have lower washers in some of the body mount locations that only are there to keep the body on the frame during a crash)
New bushings, add the lower frame mounts, new taller balljoints, U-joint lower steering shaft, and new shocks and it will drive/feel much more like a modern car.
New bushings, add the lower frame mounts, new taller balljoints, U-joint lower steering shaft, and new shocks and it will drive/feel much more like a modern car.