It all depends on how much you want to pay for convenience. Tim is right, the $ 100 jobs are great if you have a stock set up. In my case, I had a few variables to deal with. My truck has a long bed so the tail light wires needed to be longer..I also have a Hydramatic Tranny which adds a neutral safety switch and a carb with an electric choke. I also wanted the directionals wired into the loom as well. I bought my harness at
Ynz in California .. I talked my requirements over with them on the phone before they built it. Everything fit perfectly and I did not have to cut or modify anything. The instructions were clear and easy to follow. I paid more than a hundred bucks but as I said earlier, you pay for convenience. Check around and ask questions, you will find the one you need..