[quoteI wouldn't see how the tranny mount would cause this, do you mean the shifter mount to the tranny?
Sorry about that, I'll explain it a little better: It's the transmission to crossmember mount you are looking at. After they take years of supporting all that weight hitting every bump in the road, the rubber pounds and mushes out. It only takes a fraction of an inch at the mount to make a big difference up top at the shifter. You can have a helper go under there with prybar and pry up on the transmission while you watch from in the car and see how much difference it makes. Would that also cause the stiff shifting?
The grease in your shifter is all dried up and full of dirt.
It's a tedious job, but just pull the whole Hurst mechanism apart, clean it, grease it all, and put it back together. Take lots of pictures while you are doing it and try to stack everything in the order it came apart. I've done it, it's a piece of cake. 
Made a huge difference.
That must be the reason why the later shifters have a grease nipple on them. 
