AM0814-20 Oil Filled Bronze Plain Bush 8x14x20mm (pack of 5 about £12)
The holder is a snug interference fit and perfect on my printer. Your printer tolerance may vary.
Two fixing holes provided, one is slotted. Initially fit both screws, leave slotted one loose and move bed to allow bearings to pivot and align. Use nylock nuts and lightly pinch both screws, check for free movement. There may be slight resistance compared with the LM8U ball type but this is not a problem. Please do not tighten too far, a tiny amount of slack to aid alignment could be useful.
I add a small amount of silicon grease every month or so. No sign of visible wear and of course a dramatic noise reduction. Both Y axis rails are original Prusa.