Thanks for the help as far as quietness, I'll try that out...
I made the chassis flat by clamping it down and heating it, then letting it cool while still clamped down. The chassis is now flat, but I am still having the problem with preload. I am having to preload the shocks too much to tweak the car, and to set ride height equally. I just cannot figure this out, the chassis is now flat, the droop is equal, I checked it using both the droop guage and by setting the car on a flat surface and using a ride height gauge.
Has anybody else had this problem?