I’m in the process of restoring my ‘83 K5. I did lots of research on new wiring harnesses. I watched YT videos, I spoke to Painless, American Autowire and KwikWire. Autowire has good quality and everything you need but was far more money than I wanted to spend and wasn’t impressed by their attitude. I also spoke to Painless, read reviews, downloaded and read the 160ish page Painless instruction manual but was put off by the Painless representative’s attitude and knew I would need lots of technical support. Their manual is pretty good but still leaves lots of room for improvement and finally I spoke to Kwikwire and was impressed with their customer service, small family owned and operated atmosphere and price. I also downloaded and read their manual which was pretty good but also needed improvement. Because of Kwikwire’s support, reputation and price to fit my budget I purchased and received their full 27 connector harness and was impressed by the harness quality with heavier gauge wire and thicker insulation, although does not come with connectors (so the harness wires can be cut for the desired length). Ultimately, after a more detailed evaluation of my K5 wiring I decided to not use the Kwikwire harness as it would have significantly extended the amount of time to restore my K5 and I instead just fixed the bad wiring under the hood as the rest of the wiring under the dash looked great as if it had been previously replaced. So, I have a brand new Kwikwire harness and additional optional Kwikwire parts that I will have to sell and probably lose money on, Lol, that’s the way restorations go! I would definitely give Kwikwire a strong consideration! By the way, I used a combination of the Painless, Kwikwire manuals that I downloaded and ClassicCarWiring.com as invaluable references to understand, make repairs, and correct routing of my wiring. Good luck!