These are the ones I have, and they're better than the stock rubber bushing that's in there now. They're supposed to keep the caliper steady and not move under heavy braking. I will say I had to hammer these things into the caliper, they didn't slide right in but that's the idea.
Steeda Stainless Steel Brake Sleeves - '87-'93 Ford Mustang
Steeda Stainless Steel Brake Sleeves - '87-'93 Ford Mustang