I replaced all my body mount on my wagon, uppers, lowers, and a bunch of the bolts as well. I used a few 9C1 bushing up front to help tighten things up. It was a bit more work, and money than I had planed, but the results were good. The black energy suspension kit for a Caprice/police/taxi may be the best way to go, as the factory stuff is no longer available.
Mike