Do you have the stock type nylon bushings? Are the shifter arms binding? I guess sometimes you actually have to "de-burr" the arms otherwise they tend to bind. If you have the nylon bushings, you could order replacement metal bushings directly from Hurst. Also, if you use a washer on the other side of the bushing (where the retainer clip goes) that is supposed to help prevent binding.
1969, X-44, Export Model, Hugger Orange, Std. Int., BC Rear(soon to be a BT 12 bolt), PDB, GMPP 350HO, M22 Supercase, SSM Lift Bars, AirGap, Holley 750, FlowMaster American Thunder Exhaust, FlowTech Headers