SteveJ

If the meter was reading 0 Ohms when touched across the ballast resister, that means the ballast resister is just a small piece of wire. A bad resister would register as an open line or very high resistance. Just to be clear, you should be measuring from the black/white wire to the wire going to the positive on the coil. Let me be clear on what I asked before. What is the voltage to ground at the positive terminal of the coil when the key is in the ON position? To go back to one of @Zed Head's posts, did you flush out the old gas and put in new gas? Trying to run the car on 12 year old gas is not a formula for success.

If it started with starting fluid and died, you probably have more than one problem. You have a problem with the ballast resistor or the ignition switch. You have spark when the key is in start. Otherwise the car wouldn't start on the starting fluid. When you release the key, a bad switch causes you to lose spark, or a fault in the circuit is causing you to lose voltage at the coil (sometimes the ballast resistor). Also it could be that you are using up the starting fluid you sprayed in (See #2). It doesn't sound like the injectors are firing, so you don't have fuel. That could also (in part) be from a bad ignition switch. As suggested, download the FSM and the wiring diagram. Get started with a voltmeter. If you don't know how to use a voltmeter or read a wiring diagram, then find a friend who knows how to do so.

Your wiring diagram looks correct. Of course, you can look at the factory wiring diagram by downloading the FSM from this site. The condenser goes to the positive of the coil. Make sure the B/W wires are not touching anything (wrap with electrical tape). Put the key in ON. Use a voltmeter (or test light) to measure voltage to ground (I like the strut tower nuts for ground.) on the B/W wires. The one with voltage goes to the ballast resistor.

I like the adjustable flashers myself. I've used these for years: https://www.amazon.com/Audew-Electronic-Signal-Flasher-Motorcycle/dp/B011BTMDQM

If you want to see what is out there: https://www.tirerack.com/tires/sizes/results.jsp?diameter=14

Just browsing Tire Rack: https://www.tirerack.com/tires/tires.jsp?tireMake=Cooper&tireModel=Cobra+Radial+G%2FT&partnum=17TR4CRGTRWL&vehicleSearch=false&fromCompare1=yes

When you put it that way, all of the above, and I feel the same way you do.

Why not both? And, yes, I know who he is.

24012-8323 is not a valid Nissan part number. Even adding an "E" to the second part doesn't seem to bring up anything except an ebay listing that cannot be correct as there were wiring harness changes between 71 and 72 and 73 that would cause issues if you didn't have the correct harness. 24102-E8303 would be for a car built in June 71 that started off its life as an automatic. 24102-E8300 would be for a car built in June 71 that started off its life as a manual.

You'll have issues with the headlights if you use a later harness. Also, the wiring for the fuse box won't line up right. Those are two things off the top of my head. One time I was helping someone get rid of some electrical gremlins in a 71. A previous owner had cut many wires, so the guy working on the car swapped in a 72 dash harness. Lord, that took me quite a while to debug.

Part numbers can be found here: https://www.carpartsmanual.com/datsun/Z-1969-1978/electrical/wiring/to-jul-76

Probably the easiest way is to use the extractor tools they have on the website: http://www.vintageconnections.com/Products/Tools. Get the set as you will have both 2.8 mm and 6.3 mm terminals that you may want to back out. The terminals have little tabs on them that hook inside the shells. You depress the tab with the extractor tool. It helps to push the wire in a little first. After you get the tab pushed down, you can pull the wire out.

This is my preferred style of crimper to use on the terminals for the connectors: https://www.amazon.com/gp/product/B00E1JQ1UE/

When it comes to expertise, I'm full of it...wait...that didn't sound right.

No need for load resistors. The Z doesn't check for burned out lights.

2020 SUCKS!

Kenny Ueda just posted that his mother, Johnnie Gable, just passed away. If you don't know the name, Johnnie was Mr. K's secretary when he was in the US. Johnnie was a fixture at many ZCONs. She was always ready with Z car stories and could keep you entertained for hours. She will be missed.

I used PB Blaster on a plug for an O2 sensor bung. The plug wouldn't budge. I tried the Kroil, and I got the plug loose and removed with no thread damage. I should also add that if you look up penetrating oil comparisons, Kroil is usually at the top. https://www.google.com/search?sxsrf=ALeKk03g9LCNLRF-NgNXl6cC20RsdNj0ew%3A1607365501682&ei=fXPOX5qVKcugtQX-gZXYCQ&q=penetrating+oil+comparison&oq=penetrating+oil+comparison&gs_lcp=CgZwc3ktYWIQAzICCAAyBAgAEB4yBggAEAUQHjoECAAQRzoGCAAQBxAeOggIABAHEAUQHjoICAAQCBANEB5Qu-0JWMvxCWCr9gloAHADeACAAXWIAbQDkgEDMS4zmAEAoAEBqgEHZ3dzLXdpesgBCMABAQ&sclient=psy-ab&ved=0ahUKEwjax4GOv7ztAhVLUK0KHf5ABZsQ4dUDCA0&uact=5

Try Kroil instead of PB Blaster.

Just remember to unplug the TIU when using the ZX distributor. Years ago a friend was trying to diagnose a customer's car with a setup similar to yours (triples and ZX distributor). It just wouldn't run right. I asked if he unplugged the TIU. Nope, the TIU was plugged in still. Once unplugged, the car ran like it should. If the resistor is bad, you'll want a 2.2kOhm 1 watt resistor to replace it. It wouldn't hurt to get a multimeter with a tachometer function to see the signal you are getting for the tachometer gauge. That could keep you from throwing parts at the problem.

Don't bypass it. It is there for a reason.

The VIN posted by @lonetreesteve was HLS3056312. What I didn't notice is that it's one digit short. If the missing digit is a leading "0", that would put it in the range for a 72. The 76 VIN should be HLS30270001 to HLS30350000 for a coupe and GLS30030001 to GLS30060000 according to the chart below (though I suspect it might be GLS30003001 to GLS30006000 due to the lower production numbers - unless the VINs were unified for the 75 and later worldwide). They may have got it screwed up in the email they sent him. They wouldn't have re-set VIN numbers, though I think it has been established that VINs are not necessarily sequential. In my observations, it appears that the bumper indentations on rear quarter panels disappeared after 74. Here is a restoration in progress on a 75 that shows the lack of indentations: http://mybuildgarage.com/2010/09/1975-datsun-280z-restoration/ I'm not willing to bet against you for the lack of title or the parts car status. I'm not sure you could get more than a couple of hundred in parts off of that car.

Many people have performed the ZX distributor swap into 260Zs and 280Zs and maintained tach functionality. Did you unplug the TIU? The resistor is most likely on the passenger side. It is on my 260Z, but I can't say for sure on a 78.

Have you verified the resistor in the tachometer circuit is good? Do you have a meter like this to test the signal?

The VIN is consistent with a 72. The rear quarter panels, bumpers, and grill are consistent with a 72. The interior (notice the voltmeter), the tail panel, the engine bay, and radiator support are consistent with a 76. (A friend tried to use a 280Z airbox on a fuel injection conversion of a 260Z and found that the intake piping couldn't pass through the radiator support on the earlier cars.) My guess is that it was a wreck and rebuild at some point.