I learned a couple things years ago with aftermarket shifters. I always would use the metal bushings in the shift arms, both shifter end and transmission end. The nylon bushings are soft and add to the slop factor. I also always used a 1/4" (guess) drill bit to adjust the shifter arms. Put the transmission in neutral have the arms of the transmission and shifter in neutral, then slide the bit in to lock shifter in place. Then adjust each rod to the correct length. Then if your shifter has the 3/8 bolts with the lock nuts to limit the travel make sure you adjust them to make sure you are engaging each gear all the way. The last thing is to make sure the shifter assembly stays clean and lubed, it makes a big difference.
Don
