Just my 2 cents, but if you have hard shifts, it can be the neutral switch on the transmission. 1996 (and 1997?) have a TSB for that. But with time after 135k, seems good to change it anyway. Ok, I rode another post you made, it seems you have changed it. Did you change the TPS ? It can help too.
Do you know if last owner has put a trans go shift kit ? (It's possible.)
It's hard shifts on all speeds or between specific speeds (for example always between 2-3 shift) ?
I had harsh shifts on mine and I put Lucas transmission fix bottle in it and it help it a lot. (But the source of the problem was finally the gas pump losing power progressively, producing hard shifts sometimes mostly during hot situation (weather or motor). The gas pump must be changed after 135k OMOA.
Hope it will help,