Rear end suggestions

Having a similar issue as OP appear or become noticeable after going from 2.71-3.55 and adding sure grip. Found bad front u-joint. Replaced both. Checked wear pattern on gears. Good. Checked driveshaft orientation. Good. Changed out trans mount. Got somewhat better.Went from rubber to poly trans mount and got really bad so rubber mount is masking the problem. Gets worse at higher RPM like OP. Sound is like waaaaaawaaaaaaawaaaaaa. Another words not same pitch. Shaft looks good and both weights in tact. Question. Can a driveshaft go out of balance without damage? Tried the hose clamp trick at 45 degree increments and no change.