my car is pretty done up for the most part but I havnt done anything to the suspension. my car still has the original v6 springs in the rear. I am afraid that if I mess around with the suspension too much I will break the ring and pinion. Any suspension help will be greatly appreciated! I know I need some SFC's.

 

The only way you can break your ring and pinion is from engine torque. Nothing you do to the suspension will affect this. A sloppy suspension can however affect the u-joints from bad pinion angle in lowering too much or just too much torque trusts on old bushings.
The #1 best suspension mod you can do is invest in a GOOD set of road race shocks like Koni's or Bilsteins. These will limit suspension movement and slop due to their high rebound settings unlike KYB's and such.