First, do NOT use oilite. Its far too soft for the pounding the rack bushing experiences and will disintegrate. Use phosphor-bronze, and make it the same dimensions as a stocker but about twice as long. Such a bushing will outlast most owners. It'll take you a while to totally rebuild the rack anyway, so just tear down the rack, remove and measure off the original. Early racks were a little different than later racks, so by using what you have as a pattern, you'll know it will fit. FWIW, 100% of the vendors sell these bushings laughably cheap- and they fit, too.