I've spent a lot of time over the years trying different combinations of parts to get these cars to handle. I'll start the with the best bang for buck upgrades.
- Cop sway bars. Easily the best and cheapest upgrade you can perform. Get the front 1 1/8" and rear 3/4". The difference even in just changing lanes is dramatic. No more diving into the corners. You should be able to find a matching set for $250.
- Frame ties. If you drag these cars you know how flimsy the unibody is. All the work you put into the suspension will never be fully realized if what holds it all together has the rigidity of a wet noodle. I paid a local racer to fabricate and install a pair for me as I can do overhead welding. All he used was 3x1" box tube and tied the front and rear rails together. Nothing special and no bends. Didn't even go through the floor. The difference in regular street driving was day and night.
- Good shocks. If you don't go nuts with higher spring rates then a set of the premium Monroe shocks are a good choice.
- Turn down the pressure on the steering pump. Greatly increases road feel at the wheel, but does nothing for the slop at center though. This is a real cheap upgrade and can be done for $10. If you don't want to spend the money on the Borgeson washer pack you can make your own from a set of copper crush washers and turn them down using a drill motor, vice and file.
- Run 235 or 245 tires on all four corners. Even BFG Radial T/A will perform well for street driving. Stay with 15" unless you want to sacrifice ride comfort.
- Run a five leaf rear spring and run B body shock plates. Pretty noticeable difference and you gain a very wide variety of shocks as you'll use standard B body pieces.
- Use poly bushings on the sway bars, but stay away from them on the control arms and springs unless you don't mind the squeaking.
- Lower the stance of your car and keep the front and rear at the same height. This will present a problem though if you run full length headers. The driver's side will kiss the street due to the soft T bars.
The above all done together will make for a very nice driver without sending creature comfort out the window.
The icing on the cake, but more expensive.
- Firm Feel 300# torsion bars. The weakest link in the cars was always the junk T bars. Chrysler only made one rate bar for these cars at 140#. 140# sucks. Not even the cop cars got a different bar. These things aren't cheap though at $650. I love the two sets I picked up though and would do it again in a heartbeat. Road comfort didn't really take that much of a hit as I was still running 15" tires. You will need better shocks though!
- Bilstein shocks on all four corners. These have gone up dramatically in price though since I purchased them. With the cost you might as well look at a set of custom Vikings as those are adjustable.
- Borgeson steering box. Want bolt in rack-and-pinion steering? Doesn't get better than this. Faster ratio, smaller box, tight steering, no slop. Once again though, not cheap. I've got about $900 into mine between the box, lines, pump and adapters.
- Firm Feel tubular upper control arms. Nice upgrades that made a good difference in steering feel. They will squeak a lot with the poly bushings though.
Hope this helps.