Quote: The stock suspension will work pretty well up to about 150-160 mph. The biggest issue is that you run out of suspension travel when you lower the car. The car needs to be lower for aero as well as CG and looks, but the torsion bar setup doesn't have much room once you lower it.
Other than that issue, the double wishbone torsion bar front and the short front leaf rear suspension is a good combo. Good enough that TA and NASCAR used it for a long time.
Tim's Valiant has about all the tricks necessary for high speed track days. Eberg's Brick doesn't have quite so many tricks but it stills hauls the mail. I'm not aware of any A-body with tons of tricks that works better than either Tim's car or Eberg's, but they could exist. I certainly don't know about every A-body Mopar in the country!
Here is one article on Tim's car. There are several more in Mopar Muscle. Just go to the MM website and search on my name.
Although in my experiance, off the shelf full length headers will be the limit of lowering on the street before the suspension. TTI and Dougs included.
