I have had my set of polyurethane bushings on my '90 for 4 yrs now and they haven't started squeeking, the ride acually smoothed out with them as well, my cab doesn't rattle on my rock sliders like it did with the old mounts



I think your parst store is charging you a bit much, there isn't that many bushings on an '85. A complete body mount kit and upper/lower A-arm bushings from EnergySuspension for my '90 was only ran me $115 shipped to my door from Summit Racing. What other bushings are included in a kit for the '85, other than the body mounts and sway bar bushings?

Poly body mount bushings should not squeak, mine have never done so in about 9 years of use. In order for them to squeak, you would need to make them moving around and if that is happening, you have a bolt loose or something broken. If properly installed, they can't move around and no motion = no squeaking.