i just recently put shift kit in my 34 4 door. purchased the valve-body kit and the shift solenoid from M.V Automatics.
got it installed at Wangara Auto's.
its like driving a different car. gear changes are instant. 1st - 2nd can be a bit harsh but you learn how to drive it nicely.
the car will light up the rears going from 1st - 2nd now... :-) (of course this is on the track)
i went down this path as i drive a lot and like the ability to drive it like a manual or like an auto.