My favorite that I have used is American Autowire. They make good quality stuff and one thing I like is they use stock colors and gauges, so you can easily troubleshoot with factory wiring diagrams.

 

I was just looking at their website

 

100% the american autowire one. especially if you plan on adding electronics the car didn't have, like digital gauges, stereo, electric fans, etc. specifically the "classic update kit". As previously mentioned, it has all the factory wiring in the original colors & labeling every 3ft on the actual wire. Also upgrades to a larger, ATC fuse box vs the glass tube one. On the pre 67 models, you'll have to cut the firewall to enlarge the opening, since the new fuse box is larger with more fuses. The kit also comes with everything you need for a restomod, like electronic transmissions. It also contains a pigtail with accessory fuses, an assortment of ones that are batt/ignition/accessory keyed-on.

I even bought their terminal connector kit (about $100) and have used that for creating harness for everything I've installed (rather than splicing wires together). You will have to buy both their crimp tools, as well, and they aren't cheap. I think I paid about 200. But they work for any kind of the double half moon crimp style terminals for power/speaker wires.

also the kit came with things I hadn't considered, like the receptacles for all the tail light bulbs, a new ignition switch (you can use your original key + tumbler), etc

I think altogether it was $1,200 for me, with the classic update kit + the crimping tools + the convertible top wiring kit (not included in the standard kits) + the professional terminal pack. This was in 2023 though, and I know the prices has gone up. Still worth it, if you can wire it yourself. My time clocked in at around 100 hrs to do this on mine.

 

I did a full rewire on my 64 with American Autowire. Great stuff!! Surprisingly easy to do the rewire.

 

I agree with all of the above posts. Did my 64 Conv. with American Autowire. Their kits include everything you need, unlike Painless. Easy to follow schematics and instructions. Take your time, build your harnesses using plastic wire wrap tape NOT electrical tape or those ugly plastic tubes. Use a drill to twist paired wires and lay out the harness evenly and neatly as you wrap. Provide good metal to metal chassis and engine grounds, very important. Write notes on the schematics of any minor changes or locations of wires you may need in the future such as radiator fan wiring. Finished product will look very professional and eliminate electrical issues.

 

Going to have to partially disagree with you on both counts, the tape and the plastic conduit. Using cheap electrical tape is a bad idea, that is true. Using the good stuff like 3m Super 33+ electrical tape, along with plastic conduits is a far superior protection scheme vs plastic wire wrap. There's a very good reason those conduits are used on modern cars. They provide superior protection against temperatures (high & low), sharp edges/rubbing, electrical interference (especially so if you are adding modern electronics), as well as against animals (like mice). The conduits are also much easier to route and pull through the body, under the carpet, etc. Unless you're going to have the car judged against originality, plastic wrap is the least durable method other than maybe just bare wire.