4 speed to 4 speed od clutch chatter

As I mentioned to racerkilla earlier on this post, my chatter was the same severity. A guy several miles away from me had the same issue when making a simple change. After a year of fighting mine, I talked to several people with odd chatter issues. One shop owner on this site changed a clutch and pressure plate on a Dart. Let it off the rack and couldn't pull out without shaking entire car. He changed clutches and everything same deal. He then put pinion angle shims in and it was fixed. The weird part was he just drove it in and serviced the car with new clutch and flywheel no other changes. The other guy down the street from me just clamped the front of his springs to compensate for the axle rotation. It worked, but shims would have completely solved it. Not sure why this happens, but it can and will. Lastly, springs are controversial now. Some metal in these springs are non ammerican metal and have been know to be weak. I ended up going with calvert because even mopar springs are made in mexico. It sounds rediculous, but again it fixed several members issues. My father was a Chrysler mechanic since the late 60s and could not believe that this so called chatter issue could be caused by the rear suspension.