Zed Head

Are you running resistor plugs with resistor wires? I'm no expert. And I can't really tell which wires you mean are the secondary wires, or what "pulling kilovolts" means. Anyway, the oscilloscope traces would be interesting if you could paste them in over here. Pretty sure that some of the members here are electrical engineers and would like to see them.

Edit - I just saw that you're using the gap recommended for points. Can't see the traces without becoming a member of the other site. What gap are you running? The Mallory Unilite is not a "high energy" ignition system. It is electronic but runs the same plug gap as a points setup. http://documents.holley.com/mallory_instructions_unilite_distributor_37_38_45_47.pdf

If you're going to do wheels and brakes, and suspension, you might consider dropping everything as an assembly. Struts, control arms, axles, diff will all drop as one sub-assembly. Drag it out and the nuts and bolts will be easier to get to.

"Recently rebuilt" could mean almost anything. I'd get details. Primer can hide a lot. And Houston is next to the salty Gulf. Not sure they don't have rust problems too.

Looks like it might be. The N3500 number doesn't show up on any of the 240Z - 280Z diagrams. Maybe its the ZX gasket.

I posted this before but be careful when pressing on the lens. Mine lost its last bits of flexibility in just a few years. Shattered in to bits. Here's one factory bulb change procedure. They didn't have it in the early FSM's. Found it in 1976. Might be different for earlier. Looks like it just pulls out then has to be unplugged. Spring retention.

This one should work. http://www.carpartsmanual.com/datsuns30/Datsun-Z-Index/Engine-280Z/Manifold-Egr/From-Aug-76 https://www.nissanpartsdeal.com/parts/nissan-gasket-manifold~14035-p7100.html https://www.google.com/search?client=opera&q=14035-P7100&sourceid=opera&ie=UTF-8&oe=UTF-8

The CL ad looks legit. But. The phone number comes up as Skykomish Lodge in Washington state. Beware. Might be a phisherman. Or it might be a mistake. John? Good luck to anyone who tries to buy it.

People use "glass packs" all the time to replace the resonator. If you replace it with pipe you'll probably get drone. Glass packs are pretty cheap. If you post a picture of the damage we could probably tell you how to put it back together. https://www.google.com/search?source=hp&ei=MqfDW5KcAoSv0PEP96WAoAE&q=glass+pack+muffler&btnK=Google+Search&oq=glass+pack+muffler&gs_l=psy-ab.3.1.0l4j0i10l2j0l4.1477.8563..8751...3.0..0.116.1042.22j1......0....1..gws-wiz.......0i131j0i22i30j0i22i10i30.Mq2b0NCN5cY

You're off by $80,000 and behind the times lonetree!!!! John is watching. He fixed the Contact link. The price will be rising soon.

One other thing to be aware of is that when the seal wears really badly it can then wear a groove in the driveshaft slip yoke. There's a metal spring inside the rubber seal that can wear through. Metal on metal then. Your leak looks like a bad one. If the owner pulls the shaft and finds a groove you might want to wait on the repair. The 240Z slip yokes are replaceable. Good luck.

MSA does a fair job of matching their parts. Not sure why you'd want to second-guess them. Is their a part number on their gasket? If the metal ring lands in the gap between the exhaust liner and the head then it won't do much. You do have an N47 head right? The specs on the page you posted say 75-78 which covers square port and round. Something seems off.

You said puddle but didn't show one. Unless that blank video has one in it. Some video formats don't make it through, probably a phone thing. Gear oil has a distinctive smell. That rear seal is known to wear. Did he buy the car for you or is it his?

I was going to post the CL ad Reply thing for a snarky response but it didn't get through. $100,000 between privates? For a 240Z? Holey Moley.