I just replaced all the body bushings (including adding the GNX which is by far the easiest). Some of the issue's I encountered were as follows:
1. Bolts spun in cage nuts/broken bolt - happened 7 times - requires you to go in from interior of the car, cut out a section of the body in the floor, remove the old "Z" nut, and replace with a new one. I welded in a new z nut as I didn't want to weld in the whole cage nut assembly. Good news hear is that everything eventually is covered by a carpet, so your sins will be hidden.
2. Frame mount where bushing sits is rusted away - Occurred 3 times - while body is up in the air, weld in new "donuts" which can be purchased from Gbdoy/Mike's Montes (Mike Monte's were a bit more robust of an option). You can do the welding with the car lifted about 6 inches off the body on either side. The higher the body the more access you have to put in a good weld
3. Body panel rusted around bushing - required a small patch panel to be welded in to underside of body to provide required support
If NONE of these problems occur, and you are able to break all the bolts free, can easily be done in a few hours in a home garage. Because of all the nightmares I encountered, I took my time, and did it over the span of a few weeks. While I was at it I also replaced the driver side floor pan. It's actually quite amazing how much of a difference it made. Before I thought my car had lowering springs, now I realize the stance was due to the body mounts being either pushed through the floor, the frame, or just completely deteriorated...After nearly 40 years, if the bushings haven't been replaced once, and you live in the North East like I do, expect some of the challenges I had. Fortunately parts are available (z nuts, bushing, bolts, frame donuts) to help you out.
I also used this as a rationale to buy my own mig welder and learn a new skill so it can be a good project if you take your time...or you could get lucky and everything un bolts with ease
. All in I think this process probably cost me about $600 when factoring in the floor panel, the bushings, the primer/paint for the floor. I also added a new carpet and sound deadening which pushed the total job to $1000...but if all you do is replace the bushings, its just the cost of the bushings. I have to assume all this would have probably cost me 3-4K had I paid someone to do it.
