I did a search but couldnt find exactly what I was looking for. can some of u more educated guys tell me what LCAs, torque arms, and panhard bars do? i'm lookin to stiffen up my Z and make it handle a little better, are these upgrades (along with SFCs) the way to go as far as starting mods?

 

LCA's force the axle down, which means forcing the tires into the ground. This means better traction in most cases.

PHR is for lateral (sideways) motion. It helps keep the back end centered above the axle.

Torque arms keep the axle down also.

They all have to do with rear end suspension and handling.

 

Check out this thread:

http://web.camaross.com/forums/showthread.php?t=394217

 

The LCAs locate the rear axle front to back.
The PHB locates the axle left to right.
The torque arm keeps the axle housing from rotating.
There are lots of aftermarket replacements available for all of the suspension parts on a 4th gen. Nearly every one has its own particular strengths and weakness compared to the stock parts, depending on what is important to you as far as how it changes the way your suspension works, so get a good idea of what is important to you before you buy. Take it from someone who has bought 3 sets of swaybars and 2 phbs.
For starting mods, I'd look at stiffer front swaybars (I recommend Sam Strano's 35 mm bar) and start considering shocks and springs.