I found the original manual shifter to be too tall and combined with the 'circus tent' shift boot to be downright, what were they thinking, ugly.
The upper part of the shifter is a vibration damper - there is rubber bonded to the inside of the 'fat' tube and then bonded to a rod inside. Getting the damper off is a royal PITA while in the vehicle. Removing the shifter from the transmission and working in the shop would be my choice next time.
When finished the remaining shifter is shorter and IIRC about the right diameter for 10x1.25mm threads. I found the resulting location a bit too low and far away for me. So I made an offset that raised the new shift knob and moved it twards me to provide good shifting action.
Without the damper, some noise and vibration will come thru the shaft. A medium to heavy shift knob will reduce it to modest levels.

dave and xtoy - shift for brains