I did away with the backup lights never seem to be that good no way. I have all 6 lights as brakes.
I like them much better than the factory bulbs. I also added a 3rd LED brake light inside the back window.
1964 SS Impala -350 crate/powerglide
1967 Ramp truck - 350/ 4 speed
1971 C 10 - 6.0 LS / 4l80e 4:10 gears 30 years owner
94 Elderado
2000 S-10
2008 LTZ Tahoe
2011 Treverse
I have been using LED tail lights in the 61 for several years. I purchased them from Easy Performance and loved them so much I bought two other sets for other cars.
The set I used from Easy Performance has a provision for reverse lights, however I opted to custom order them without. For everything to work properly you will need a no load flasher. They aren't expensive and the same company sells them.
They have several sequential patterns or you can just have them all on - all off like normal. I chose them because the service of the company and the performance of the product - they are very bright (see video below).
The kit from Mustangprojects above is plug and play and comes with a new flasher which you can set to your liking. Also comes with the 2 extra sockets to replace the backups lights which you will have to splice into your harness. As far as the back up lites I just tucked them trunk lid in case I need for any reason in the future.