I went through this on my truck (mice had eaten all of the back wires) when I first got it. Ordered the new wire pigtails from LMC for the back up lights and they didn't work. That was actually the start of my education in "do not buy anything from LMC.....EVER!"
Anyway, I ordered these and they work great. Would highly recommend them.
https://www.classicparts.com/1967-72...ctinfo/50-043/