How are you determining "tight" ? The bushing will continue to compress as long as you tighten.
Spec. for the upper shock nut is 25 FT.LBS. Just snug.
I removed the stock bushing and used the two peice ones that came with the shock. Seemed to work ok, but I have not driven the car since I replaced them.
Hmm, I wonder if I tightend mine too far. Cranked them right down and compressed the bushing quite a bit.
I guess I should break out my torque wrench and redo it to make sure.
Jas