The M-20 Heim bushing is used in the 5/8" heim of a funny car a-arm to allow a 1/2" bolt to be used. The bushing is made from 3/4" RD 4130 steel and measures 1/2" I.D., 0.622" O.D., and length is 0.735". There is a pdf chart that can be downloaded from our website, http://mckinneycorp.com/downloads/pdf/bushing.pdf, that will give you a list of some of the bushings that we carry. Should you not be able to find the bushing that you're looking for, call and we'll be happy to assist you in finding what you need.
