The older cars had the back up light switch on the top of the base of the steering column. Not on the trans. He wants do away with the switch on the column and go to the one in the shifter. On the later cars you don't need to do this beacuse the back up lights work through the trans switch. Also you can't just change from a single terminal switch to a three prong switch because the cockscomb on the valve body is different and won't work.