Big Block Abody with factory front suspension

It probably doesn't like the radial/bias-ply mix very well.
That may not be the whole problem but you might try bolting
a pair of radials on the rear and see if there is a change.

This is still a rear steer isn't it?
im thinking change the front tires to the bias ply drag tires by phoenix fx which is the same as the old firestone slicks in the rear there made of the same compound. the size will be 24.5 x 4.5 x 15 it now has a 185 or 165 x 90 x 15 radial im sure the previous ower bought them because they were cheaper than a real drag tire they also rub the headers when turning i think betwwen the tires and the steering gear and a alignment it will be better.