Older thread but still valid and helpful . Figured I would add my experience and fixes . I have a 27 T on a custom chassis , suicide front end , bias ply tires , spring and tie rod are behind the axle , Front tires set to 20 psi , hydraulic shocks. Car would be great up to about 60mph , any bumps encountered above that speed would turn the front tires into a couple of basketballs. No wobble just bounce , up and down . Had the front tires Road Force balanced and put Dyna Beads in that helped some. Reset the toe in from 1/4" to 1/16" , that helped some. I disassembled the front spring and found that there was rust between the leaves and no apparent movement. Installed Speedways finest poly spring liner , reinstalled the spring and went for a ride. That did the trick , no more uncontrolled front wheel hop . It can get a little busy at 65mph on a washboard surface but it stays under control. Pete