I'm using that exact harness. If you have a basic understanding of wiring, it's not hard at all. All of the wires are labeled, and you won't need many of them. The main issue is that the Painless kits are made for a front-engined car - so the "engine" section of the harness will need to be extended, while other sections might be too long. It's no big issue, just takes some time to adjust the harness. Some might say that you destroy the heritage of the car by tearing out the old wiring. I say it's better to have new, reliable wiring, than 30-year old wiring from any manufacturer. Plus, who's going to see the wiring. Nobody. I love my new wiring, and now I can drive/race the car without worrying about it. Prior to the install I had all sorts of electrical issues. All of my gauges work now, imagine that.