Converting column auto 3 to 4 speed

Has anyone converted their column shift auto to be compatible with a TH700 auto? From 3 speed to 4 speed and how did you connect it up to the auto?
I have seen the Lokkar brand cable shift products which mount to the bottom if steering column but feel it will interfere quite a bit with the headers as there is not a lot of room.
Another option may be converting a column shift from VN/VS commodore ute, if anyone has looked into this option i would also be very interested

Any help would be much appreciated, I really dont want to mount a floor shift if possible