If you have to ask, then the answer is YES.
I have replace all my underhood wiring, except for the A/C specific harness, since I am not using the A/C at the time...pending the paint job on my truck.
Go to
www.wiringharness.com for the website for M&H Fabrication. They make reproduction harnesses and can modify them for 1-wire alternators or HEI distributors. The color code is as new, and all connectors, brackets and covers are already in-place.
I liked dealing with them, better than someone like LMC. LMC is just a jobber and knows very little about what you are ordering. M&H builds them and you can call them and ask all kinds of questions.