I used *cough* Ford light sockets that were two wire (hot) with a ground wire and used one of the speed nuts to body for each rear light (1964 Skylark) as I had weak and "flickering" issues prior due to the sockets not grounding well. Since I had to replace them anyway, I decided an extra grounding step, couldn't hurt. Also re-worked any and all sockets and grounding bonding, bumpers to frame, ground straps in several places. Very important, since almost all current for everything is passed through accessory to body/frame and back to negative of battery in order to work. Resistance is your enemy given the limited amount of power supply, and resistance, heat, load all suck it up pretty quickly. LEDs really give a lot of relief to the electrical system. All my lights work, are bright and very obvious when I step on the brakes. Given the intensity in the past 10 years, the yutes of today, never having grown up looking at dim, washed out lighting and "training" themselves to be aware of the world around them when driving, I am doing everything short of dispensing Chaff and Flares while jinking like a Jack Russell on crack.