The T bird has different idler arm bushings for manual or power steering. Manual steering has an arrangement of lefthand and righthand threads and these are grease lubricated. The PS has a rubber bushed idler arm. These operate on the same principle as the inner A arm bushings. The rubber can deform in these applications because the range of motion is very limited. This is good because there is no rubbing and therefore wear. The Poly bushings operate as a more traditional bearing, there must be rubbing because Poly will not deform like the rubber material will. If your rubber bushings are in bad shape they will degrade steering but I doubt that there is a big improvement in steering using poly over rubber.
People use Poly bushings when they are attempting to seriously control the geometry of the front suspension because the rubber bushings will also compress under load. The poly or graphite bushings that are put in A arms do not compress but they do wear.
BTW I have not found any poly or graphite bushings that will replace the rubber bushings of the first Ford Ball Joint front end as used in 54 to 56 Fords and 55 to 57 TBirds.. They seem to exist for the '57 and up Ford designs.
BTW where are you in UK? Did you recently aquire your Bird from another owner in UK? I come to UK about once a year but I have already visited in 2009.
Doug T
The Highlands, Louisville, Ky.
