Polyurethane is a harder material than the original rubber bushings. When you compare them side by side, the poly seems like a hard plastic. So hard, when installed, some bushings will squeak. Grease may break down those bushings, over time, so the graphite impregnated polyurethane bushings resolve that.
I've put all poly bushings on an e-body front-end (and rear) rebuild, and I was a little sorry after. It definitely improved handling, and cornering, but it was a little too stiff for my taste. I could feel a great deal more feedback through the steering. Sometimes, it seemed like I could even feel when I ran over a pebble. The first few weeks, it was pretty awesome. But after a few years of driving, I miss some of that lost comfort in the ride.
Rebuilding the front end is not that hard, and honestly, I find it pretty fun. I've done 5-6 (B & E body) of them over the years, and I really look forward to doing it, when the opportunity comes up.
For a one-time rebuild, it's ideal if you can find someone to borrow the tools from. But to do it, there are some special tools that make the job easier. Removing the ball joints can be frustrating if you don't know any tips or tricks. So watch some you-tube videos and learn.
One client, took their car in to a suspension shop and had them break loose all the difficult ball joints and connections, then retightened them back up, and he drove home. When I went over to assist in the rebuild, things came apart pretty easily.
There are (for example) stronger control arms, and other parts you can replace. The car won't "look" factory after bolting on some of these items. And frankly, the OEM factory design is pretty decent. Keeping all the structural parts, and just replacing the stuff that wears out, still produces very good results. You'll want to replace all the bushings, upper & lower ball joints, and the tie-rod ends. Some also do the steering and pitman arms.
The suspension rebuild kits are okay. But not ideal. You don't usually get to pick and choose the parts you want when buying a kit, and some of them contain inferior parts. Moog and TRW used to be some good names to look for, but things may be changing in our current (everything from China) buying world.
Take your time with this, and learn about the rebuild and what parts to replace. Enjoy it, because it is fun and can make a dramatic improvement to the handling of your car.
