Well took my truck out the other day. When I'm turning left or right you can feel and hear a clunk in the rear end. Only does it when turning. Could it be the spyder gears or the posi-Trac unit ?

 

Mist likely the positract. Change the oil and add friction modifier.

 

I would check to make sure your axle flanges are tight, and that your leaf-spring u-bolts, shackles, etc..are all still tight.

The limited slip is a set of clutches, and I can't really see how they'd make a clunk unless something went really bad.