Unsure of what wiring harnesses I need

[levix]

I'm redoing the wiring on a 73. I looked at painless / ez wiring / yearone and I figured since I'm inexperienced I figured I would just take the easy route and order 4 replacement harnesses from Evans wiring. The painless / ez route seems like it would be a lot of work especially since I'd have to bypass the bulkhead, and yearone is pretty expensive.

There are 4 'plugs' on the bulkhead. I know the two big ones are the engine and headlights. I know one of the other ones is the NSS, is that the one shown in the pic? What is the last harness plug?

As far as the engine harness goes, I've got 440+6, an electric ignition with MSD. 80 amp 2 phase alternator, AC, an electric radiator fan, and a 3 prong electronic voltage regular (should I be using a solid state?). The previous owner left in the ballast resistor but I've been reading on the MSD setup and seems like it's best to bypass that.

So if I wanted to buy everything I needed from Evans what would that include?
- Engine harness (not sure how difficult it would be to modify for my setup...)
- Headlights
- NSS
- 

Sorry for the ignorance, I'm new to the car world. But it is great fun 

[b5blue]

Don't 73's have a funky "seat belt interlock"? It prevents the car from starting if the seat belt is not buckled, there is a compression switch in the drivers butt cushion that is wired through the buckle and then to a relay under the hood with a button on it. (Or use to be.)    

[levix]

I was able to start the car without the seatbelt fastened before, but that's not to say that's normal. I don't see anything that looks like a pushbutton on the engine harness, but there is a very strange looking cylinderish component attached right above the old ballast resistor. Will post a pic when I get home.

[levix]

The harness in the picture is indeed the NSS. I went ahead and ordered my parts from year one in an effort to alleviate the amount of headache wiring would be.

[b5blue]

 

[Nacho-RT74]

that's a 72/73 tranny harness... If green, the extra wire is for A/C-Heater blower.

74s are the interlocked cars. 72/73s only got the warning system linked to the NSS due the warning signals are linked to the gear you are set.


being more specific:

A-Bulkhead plug
B-Starter relay
C-Mostly sure Blower wire
D-NSS plug


the 4th wiring on you list what you are is the wiper harness