I have a Kit from Global West to use G-Body spindles on the A-body. The G-body (think 87 GN) was made with radials and modern handling in mind. It will drop the front end about 2 inches. As Bob stated, a larger or any sway bar in the rear is helpful with sway. The Trans am from the 80s also had a larger front sway bar that can be used on the 60s A-body. So, the junk yard is good for those and spindles. Global West also makes rear trailing arms that set the pinion angle better for handling. Then, as discussed, a good set of shocks (Koni, Viking) will finish it off. You will have to figure out how far down this road you want to go. It can get long and winding!