Thanks guys,
Yes, they came with nylon nuts. I purchased the kit from LMC trucks, it was the polyurethane kit as opposed to the stock oem rubber kit.
I don't know what you mean budman when you talk of spacers. Basically the cab sits on a polyurethane bushing (donut) then washer, then frame, the polyurethane donut, then washer then nylon nut.
Any more suggestions??? I hope the 40 foot pounds is okay. I drive the truck daily, have hit many a big bump, and they look like they haven't moved at all.
Thanks again for your help!