Back up light problem

I have a 68' barracuda that came with a three speed on the column with a slant six. I pulled it and put a small block 318 and a 727 auto transmission out of a 73 dart.

It now has a console. i used the neutral safety switch and back up light switch in the trans. now the back up lights are on in reverse, drive and low but not in park and neutral???????

any suggestion.... do i need a switch in the console.

If the transmission really is a 73, seems to me it could only be a bad switch, or something wrong with the transmission rooster comb. . You DID disconnect the original backup switch on the shifter?