You know I asked the same question a few months ago and didnt really get a response. When I talked to ord about they didnt have any greasable bushings available for them. I was standing there for about 20 minutes with a tape measure in one hand and the phone in the other hand. After searching some parts stores all I could find was rubber bushings for them. I ultimately went to 4 wheel parts, which carried some polys that came from energy suspension, sorry dont know the parts number or I would give it to you. Anyways, got the polys, cut some grooves in them, drilled a hole in the metal sleeve, and contacted ord about the bolts. A few weeks later I had my greasable bushings in the 57's. By the way all energy sells is a complete bushing set which comes with the shackle to frame bushing as well. And to add to this, I do believe that they might be a metric size bushing, I wasnt coming up with a number that seemed to make sense at anyone from ord that would be a standard size. Good luck, keep me posted.