I experienced the same trouble you're having when I attempted to replace my front grill bushing a few months ago. I was fortunate enough to still have a tube/roll of body mount material from a fiberglass body swap many years ago. It's a very dense rubber-like material in roll with a hollow center to allow for body mount (sleeve) bushings and hardware (picture a roll of hard salami with a hollow center). The center hole in the roll accomodates the metal sleeve perfectly. Since it's a solid roll, you have to cut off each bushing whatever thickness you choose. You can cut it w/a hacksaw, but it's very difficult to get a straight cut that way. The best way is to go to a metal shop w/a band saw. It's like a hacksaw, but motorized, very stable/controlled and most importantly, cuts a straight line through even thick objects. I bought my roll in the early 90's, I'm pretty sure from 4WD Hardware, Columbiana, OH. Good luck.