please help

The reverse lights could be a switch in the trans. If i remember correctly there is a switch off of there that comes on when put into reverse. I could be wrong since my reverse lights still dont work.

Reverse switch on Torqueflites since 69 is on the trans, part of the NSS. It has 3 terminals. Center is ground in park/ neutral, outer two are reverse

Earlier cars had the NSS on the trans, the reverse switch in the shift linkage.

3--4 speed switches were always on the gearbox