I am using the 8 circuit universal harness # 10307 from painless. It is a very basic kit. I have no heater, wipers or stereo. I also have after market mechanical guages and a complete MSD ignition system. the only thing i really need is my lights/signals,charging system and ignition system. My car is about as basic as it gets. I will have 3 accessory circuits open on my fuse block. this harness is also modular and i can expand easily if i so desire down the road.
I plan to run a power and ground wire from the battery (in trunk) to a "terminal junction box" up under the dash. This way i can run power to my fuse block and my msd ignition box up (under the dash) and not have to run multiple power leads to the post on my starter relay.