shakes at highway speed

fanofpettyI had the same symptoms with a cuda I had years ago. The car had bias ply tires on it, so I put radials on it , and that cured it. cars that are sprung to stiff will feel this way too.

I have new radials. I do have new SS springs in the rear. The torsion bars are the stock ones.

FISHBREATHHmmmm. Car feels fine on smooth roads, but vibrates all over the place on rougher roads. How are your shocks?

They are new, but they are cheap Monroes. I should upgrade.

Another is that your suspension and/or steering is too lose from worn bushings or ball joints. It could be OK on smooth pavement, but jiggers around when excited by bumps. Jack it up by the frame and tug on all the wheels to look for play and look for severely cracked rubber in the bushings.

My suspension has all been rebuilt except for the the steering gear, but I'm going to crawl under the car and double check everything.