Its not a Mustang. Its not a modern car.You are driving something that was designed in the 50s. The 1950s. Thats a sixty-plus year old design.
You will need to increase the steering axis inclination, Crank up the caster, fix the bump-steer this creates,Redesign the steering box, and get some really stiff sidewall tires.Most of this is not do-able.
-Having said all that, there are a couple of things that you can do.The first is to crank as much positive caster into it as you can find. This requires, at the least, the problem-solver bushings..You are hunting for 6 to 7 degrees of caster.You are not likely to get it on our A-bodies, but 4.5 to 5 is doable.
-Then as Joe mentioned, try and find up to a half a degree of neg.camber. You may have to give up a little caster to get the camber. If you arent concerned about cornering, forget the camber, just go for the caster.
-Your ride height and stance will play a role in how much caster you can actually get.
Once these are chosen, consider them fixed, as in no longer adjustable, because any change in ride-height and stance, will change the alignment.
-If the toe is not right, it will lead to; hunting on uneven or rutted surfaces,wander,twitchiness,Inability to drive a straight line without constant correction.
-And finally, Make sure the steering box is internally centered, when the wheels are pointing straight ahead, irrespective of where the steering wheel is.
If your car tends to go off in unsteered directions when travelling on,or encountering, bumpy road sections, and most especially if just one wheel encounters a bump/hole, then the car is suffering from bump-steer. You will have to get that fixed.
-You may be back in the alignment shop several times. I was employed in such a shop when I was tuning my suspension/steering. I had unlimited after-hour access to the bay and rack.I saved hundreds and hundreds of dollars that summer.
-Wheels. One thing I found out is that your wheels need to be very close to zero offset. Changing the track width,affects the scrub radius. If you get it too far off, the self- centering feature suffers. My wheels are offset to increase the front track. I live with the feeling.
