Need Help ID'ing Parts

[dkooi]

I took the crossmember off my 72 Chevy 1/2 ton and had it powdercoated a while back. Well I'm getting ready to start putting it all together and realized that I left some bushings in the crossmember and melted them. These are the bushings that are in the crossmember holes that the bolts go through that hold the upper a-frame in place. They appeared to have been steel bushings encased in rubber, but it's hard to tell now. I'm just wondering what exactly these are called and where I can pick up some replacements. Any advice is appreciated!