I have the Pro3i street/race versions with the spherical bearings. Those are the ones you want. Poly's can be noisy. Installing them isnt too bad. You'll need to jack the back up, put some jack stands on the frame near the torque boxes, just make sure to keep the out of the way of the lca's. Put a jack under the axle, take bolts off lower shocks and quads, disconnect brake/ABS cable bracket on LCA's, disconnect the sway bar, drop the jack and lower the axle, springs should damn near fall out. then you unbolt the two bolts that hold the lca on and their out. Depending on how wide your mufflers are, you might have to unhook the tailpipe section to get enough room to get to the forward bolts on the lca's.
* 99 GT NMRA CS