NewZed

Voltage "popped up" while the engine is running, right? You are using a good meter? Sounds like your voltage regulator Sense wire is not sensing. You should focus on the "burning up" fusible link. Fusible links are there for when things aren't right. So, obviously, something is shorted, probably, on that circuit. Check the wiring at the starter for starters. And use your meter to be sure things aren't shorted, before connecting the battery.

I was just trying to make the point that fuses, fusible links, starters, alternators, etc. are pretty easy. Complete wiring harness swaps are hard. You have to break them down into components and sub-harnesses. Beside that your question is really "where is the short that's causing my fusible links to melt". That's your #1 problem. Not 12 volts to block, or why does'y my car run? Just being blunt to let you know it's not going to be easy. Good luck. Take good measurements, measure continuity back to the positive and negative cables before connecting the battery to be sure things are right.

Not a bad guess. Here's what they used in 1975-77. They changed it in 1978. Note that the PCV system pulls air through the crankcase. So the crankcase needs to be sealed otherwise less air passes through the AFM causing less flap movement. Emissions chapter.

The bumble zee guide is for people swapping only the EFI harness, Replacing the entire car's harness is a much bigger project. Use the 1983 FSM Electrical chapters if you want to see the diagram of how Nissan did it. A diagram is better than pictures. Seems like you've overshot your abilities and will have to get them caught up to what you're trying to do. Worrying about "engine block getting 12 volts" shows that you're quite a way from where you should be. Study up on basic automotive electrical concepts, like how and when current flows, what the voltage readings mean, what the fusible links are for, etc. No offense intended. You should be comfortable with this anyway after you get beyond this one simple problem. There will be more, that are more complex.

Disconnecting the alternator was a good idea. Isolate the various components. Don't overlook that the electrical system is centered at the starter lug mainly for convenience. The white wire from the alternator that runs through the fusible links could be connected directly to the battery positive, for example. You might have a shorted starter. Realize that the end of that white wire is branched to several subsystems on the way to the end of the battery positive cable at the starter. As you isolate each component, like the starter and/or alternator, and study the fusible link wiring, you'll probably figure out where the short has to be. Consider completely disconnecting your transplanted EFI system, to be sure that the basic wiring is correct. Then add the ZX EFI sub-harness. You might have just switched a wire on the 76 harness by accident. Confirm that the original parts are still correct.

Fusible link covers Trouble light covers Vent louvers for 77 and 78 vented hoods

What kind of cores?

Could also be that you connected your battery backward the first time. It's pretty common. Once the fusible links melt they don't conduct anymore. And you might have melted your ground circuits the first time. You can use your meter to confirm that things are right before replacing them. Check that you have continuity where it should be before connecting any power. You shouldn't use smoke as a troubleshooting tool.

The fusible links would normally just melt, with a touch of smoke, maybe, if there was a short. So the sparking doesn't really make sense. The 12 volt reading is correct, as you described it, to the block. What you mean by "chassis" is unclear. In short, it's not clear what the problem is, besides some sparking. Not sure what you mean by "it".

yes its easy just s and l and the solenoid wire and the charge wire and the battery cables. you can ewven use a screwdriver if you want to avoid the solenoid wire

The basic problem is that the studs are commonly NLA. You have to find old stock, apparently. You can start at #175 here - http://forums.hybridz.org/topic/78123-subaru-wrx-sti-r180-side-axles/page-9 and again at #237 http://forums.hybridz.org/topic/78123-subaru-wrx-sti-r180-side-axles/page-12

Never heard of a "kit" for that. There's not much to replace. If the boots are okay, all you really need is a new clamp to hold them on. A CV boot clamp would work. All you'll really be doing is replacing old grease.

You can search around John Coffey's threads on the axles for the Subaru diff and you'll find some part numbers, I think.

If you decide to try the machining to make it work, you might look in to another heat treatment to get the desired physical properties, if you can't determine what you have now. Although I think heat treatment can change your dimensions.

It's the shape of the teeth and the grooves that will get you. I picked up a J30 diff because it has a 28 spline axle (just to mess around with, I know that the VLSD has la longer axle) and found that the stock Z axles were sloppy in the J30 and the stock J30 axles were very tight in their original home. Can't remember if I tried the J30 axle in the Z R200 or not. That's why I bring it up though,. It's more than number and diameter.

Sorry Joe. I knew there was another supplier out there. This is the one, right? https://whiteheadperformance.com/product/whp-billet-cv-300zx-z31-turbo-axle-companion-flange-adapters-27-spline-datsun-240z-260z-280z/

Have you stuck an axle through there yet?

That's a good find. Seems worth a look. The axle, at a stress riser, is where failure usually occurs at the hub. Their ad copy says "forged 5140" which seems to have some high stress uses, according to the internet. Cranks, for example. Not clear if they are cutting blanks from forged steel or forging the shape and machining though. Proper grammar would say "blanks forged from 5140...). Anyway. "Our Blank Output Flange is made from forged 5140 chromoly steel. " Number and diameter of splines and shaft won't tell you if it's a good fit for the axle though. You won't know until you try it. Spline shapes differ. You'll need to do some machining also, either a new distance spacer, or the flange, to fit the hub. Still interesting though. I'd spend $30-40 just to mess around with it.

Kind of looks like you didn't either. How would he know that Joe's out of stock if he hadn't contacted him? First post. Besides that it looks like he swapped his 240Z parts for 280Z and that's why needs 27 splines instead of 25. He confused the issue himself by leaving that out. Words....

What brand of header is that? The hot spot is at the junction of the four pipes. Maybe it's just a poor design with a a flow restriction and thin metal.

The pilot bushing, while small and simple (dull) and cheap, is very important. It supports the end of the input shaft. A loose pilot bushing can let the shaft rattle around. You might ask the shop. Any decent shop would know, it's a normal part of clutch replacement.

There's a nut on one of the shafts that's known to come loose. It affects shifting also though. Did you have the pilot bushing replaced when you had the TOB done? Also noticed in the other forum post that you said it makes the noise in the lower gears, but not 3rd and 4th. Might be meaningful. Good luck.

If you know some people with Z's or the same transmission you could take a ride and compare. I've had four in my car that all make the same noise, they all sound like they need work.. Did you find anything on the magnet when you drained the fluid?

Nobody said that Redline would help the noise BUSZED just made a point about thick oil damping the noise a little bit. You're not being very clear on what the noise IS,beyond a "rattle". A video might help your cause. To be more clear on this end, the bearing noise is more of a dull internal rumble than a rattle, that goes away when you press the clutch pedal. If you have a real, "bare metal shaking around" kind of noise, it could be something completely different. And Redline fluid isn't going to fix the bearing noise anyway. Edit - just saw your post on another forum where you call it a "chatter". Words are all we have out here, you have to pick the right ones and use them the right way, to create an image. Edit 2 - it also looks like you're getting your various suggestions confounded, like talking about Redline in this thread that never mentioned Redline. You're going to create a mass of confusion.

Fuel line modifications, among several seemingly small things. Read through the FAQ's on the L6 engine. Study the Z car terminology. For instance, we usually call the air flow meter an AFM, not a MAF. And an intercooler is a secondary item, not really necessary to "make the car running". http://forums.hybridz.org/forum/90-l-series/