How do you know when your body mounts are bad?

[James Lamb]

I used polyurethane ones. I've seen all the arguments for and against polyurethane. Honestly, you could put a ham sandwich in there and it would work better than 30+ year old rubber. Main reason I went with urethane is they are designed to not need the internal metal supports the rubber ones used, and which are both highly corroded and semi-permanently bonded to the old nasty rubber. You reuse the large concave "washers" that are on top of a few of the mounts like the ones on the sides under the doors, and my kit came with new large washers for the others. I had to order 4 bolts from LMC Truck as some of the bolts were very badly rusted, and the bolts are not all the same.

It made a marked improvement in ride quality. The teeth-rattling jar when hitting a bump on the highway is gone. And I had already replaced all the springs and all the shocks. Surprising how much difference it made really.