I have a 1966 Fastback. Shelby drop,new roller spring perches and cut about 3 inches off the front springs. it actually drives really nice and front end alignment is spot on. tires wear normal. my problem is if i'm driving down the road over 20 or 30 miles per hour and i hit a decent bump or drop in the road especially if it is during a slight turn the whole front end starts bouncing and wobbling. once i hit the brakes a little it smooths right out again. everything looks tight underneath. at a loss !!!! anybody have any ideas ???

 

Have you replaced the shocks? Bad shocks can cause that.

 

Certainly sounds like shocks.