Hi, you can't replace the rubber on the shifter because the "service" part is no longer available. 2nd question: & there is NO bushing that goes in the hole on the 67 & up shifters. There is no way to put any bushing in the hole. As it is the exact same size as the rod ends(adjusters). It is impossible to replace the rubber molded ends on the transmission levers. There were never any parts to replace them offered by GM that I am aware of, (only NOS levers; if they can be found). I made new levers for the 1-2 & 3-4 shifts for all 67 & 68 w/4speeds. I decided to make them so that they accept the bushing(

Pit-pack) instead of the rubber molded ends.
Peter Serio
Owner, Precision Pontiac