I'am also in need of castor rod bushes and have looked at std & urethane
the std urethane no offset are the cheap option, but offer no adjustment.
I,am looking for something adjustable at a reaonable price. The closer
you get the alignment to correct the better for tyre life.
Have a look at these options
http://www.uniqueautosports.com.au/images/...ds_Mvc-064f.jpg