Transmission and Gear Shifter Question

Ok.. once again with the questions :P

car... 1978 Camaro Z-28
Tranny: TH-700-R4
Engine: V-8 350

Question:

Tranny isnt the stock transmission... this was dropped into the car before I purchased it.. the person that dropped it in wired up a manual switch for the OD....

If I put in a new shifter .... say a B&M rachet shifter would this do away with that switch or am i going to have to keep it...?

my guess would the that the switch controls the converter lock up, and if that is the case, you would have to keep it. If it just shifts the car into OD, then you should just buy the correct shifter with 4 forward gears, and get rid of the switch.