using neutral safety hookup on 4sp

Hi all,
Couldn't find anything on this in the archives... Just converted from 904 to 4 sp on my 65 valiant and would like to use the old neutral safety switch so that the car won't start unless the 4sp is in neutral. Believe that all this wire did was provide a ground... Is there a way to use it with the back-up light switch on the tranny itself? The switch on the 4sp has two prongs.
Thanks for the help!
Patrick
Author: admin