A 3-link avoids all bind through bumps. A properly set up 4-link can too, but it's not that easy to do. The factory truck arm suspension, all though not bad, isn't adjustable and can cuase binding issues too.
Here is what a 3-link looks like. This is my 73 road race car I am building.
http://ls1tech.com/forums/showthread.php?t=644613
I went with a PH bar due to packaging. Will there be rearend shift through a bump? A little. How much is based on how long the PH bar is.
There are also pics of the front suspension. Had I to do over again, I most likely would have went with C5 or C6 parts. Why? Easily replaceable, light and proven. Mustang 2 stuff is not a bad option, but I think you could get more tire under it with C5 or C6 parts. Either one though has a large aftermarket for brakes ect.. The nice thing about the C5/6 stuff is packaging for your springs. They use a leaf in the front and it sits low and out of the way.