My urethane ones have been put back in the box and are on the shelf. I tried them on the street car but were too solid and noisy. Harsh and squeaky even with the special lube. The good old rubber ones are great! The urethane ones for the race car split the first track session and have been replaced with solid aluminum ones. Nicely harsh and I can't hear a darn thing with the open exhaust.

Good tips.  They came with brackets stamped from flat stock.  Part of the zerk would protrude into the bushing so the hole to the bar would be OK.  A considerable amount of shaving would have to be done if they were to go in the OEMs.  Probably a belt sander would do the job. 

While brainstorming at work we decided the thing to do is cut the other side to make two halves and screw them or wire them back together.  I had forgotten this is what I did back in the mid 80s when I had a differant size bar and made bushings out of Delrin.  I also had end link bushings that were Delrin or something that were used on Trans Ams.