On the aluminum tail wheel be careful using metal to metal have you ever herd of RF problems with rubbing meterals. It can key up right frequency it can screw up your radio in flight . Try to use a carbon fiber or plastic bushing to hold it for the axle. Sometimes good ideas need testing out . I am sure there is someone who can tell you better what can happen. I used a sullivan 60 size on mine works great Good luck show a pic when it is done SL