GTSBoy

It's not just unverified. It's obviously not correct. As if there is a 1990 GTR around with only that many km! Comp test and leak down test it. If it comes up fine there is no reason to take the engine apart. The weak part of any RB is the oil pump. Read up about what you should do about that. The rest of it is just fuelling and oil/crankcase breathing control. Do what you have to do for those to keep it healthy. f**king crack testing the block and changing the water pump are a sure sign that your local shop have no f**king idea what they're doing, so run a mile right now and find a mechanic with a clue.

Do the calc yourself. You know your diff ratio. You know your tyre size. You know 5th gear ratio. You might have a better idea of how many revs it might pull at the top end of 5th (based on how much power the car makes, which we don't know either). You don't even have to do all that. Just drive it at 4000rpm in 5th. How fast is it going? Double that number for an 8000rpm top end. take 7/8 of that number for a 7000rpm top end, etc.

Perhaps if we understood why it matters to you.......

Yes.

Dismantle the main headlight switch on the binnacle and clean the contacts.

Speak to Kelfords in NZ about cams, etc.

If you use rust converter and then a self priming paint (like the Duplicolour chassic & rollbar paint) then it will all be good.

Send head to head shop. It probably isn't as simple as "digitsing, welding up and copying". The broad shape of the chamber can probably be done like that but any damage around the valve seats probably can't be fixed that way, and it would need to go to the shop anyway. Might as well just skip the geek-fest fun part of it and get the whole lot done by someone who's done it before.

I was guessing Ireland or Scandinavia.

As to diffs.... For proper drag, you want a good mechanical diff in the rear. Only needs to be 1-way for drag, which will also make it more livable on the street. 1.5-way if you want a bit more clunk and bang. The nicest diff in the front is a Torsen/helical. The Quaife is the obvious (and probably only) choice.

And a matching crank.

It's been exactly since the update and the appearance of the Invision changed.

Super high lift cams usually require clearancing of the bucket bores. This is a full head dismantlery exercise. Super high lift cams put quite substantial demands on the valve springs. They need to be able to take the lift without binding and to control the movement of the valve over the nose of the cam. Granted, it's not so bad when it is just high light at low total duration as when it is both high lift and long duration. Of potential interest is trying to get a cam profile with a really wide nose, to try to give the longest time at the highest lift. This will still give rather steep ramps (like a long duration cam would), but is probably worth it. But you would need/want to talk to a local supplier in Oz or NZ to discuss. You won't get it from those Jap cams. Lighter valves worth thinking about for all the above reasons. Lighter retainers, etc also.

I think he might be after the loom plugs.

300HP at the wheels? No need to change any internals and the turbo can be quite small. That's basically not much larger than a stock RB25 turbo and not a lot of boost required. You could do it with a highflowed 25 turbo and not much more than a bar, if it would even require that much. Or you could look at a GTX-3071 or similar.

You really want me to spend a half hour looking at a wiring diagram for you?

Fix the stuff that is obviously broken, obviously. All the engine bay rubber stuff, timing belt, water pump. Plan to do that immediately.

The wires literally START at the 12v rail and run to the earth rail. I have NEVER seen arrows on an automotive wiring diagram. This isn't kindergarten. Just follow each wire back from the plug (on the diagram). One will go earthwise and the other will go to a power source.

What do you mean lol? I had one. It did that. Except the death part. I f**ked it off for a Toyota before it failed.

Nah. Subies are famous for head gaskets from the first until the last. ~2010 Forester and anything else with that woeful EJ253 or whatever the hell they call it. 130000 km + or - and they will start to weep at the gasket. Don't fix it within 15000km and it will shit the bed.

More boost.

Many cars will push a little bit more coolant out to the overflow bottle every now and then, and will lose it if the overflow overfills. Then when it cools it will pull in some of the original overflow volume, leaving you with less. If this happens a few times, it will look like it is being lost in the engine, when it's not really. Some engines will lose some through seal leaks, drips, etc. Subarus will usually lose it because they are shitboxes in which a blown headgasket is a matter of when, not if.

You can always work out which wire is which and where the power comes from from the wiring diagram.

Firstly, it is ~30 years old, so it will not have 85k miles on it. It will be lucky if it is less than 185k miles. Is it still the original RB20DET? If so, budget on an engine upgrade to something that can make it move. RB25DET Neo, VQ30DET, VH56DE, LS3. Anything. If it is the original engine then everything rubber is suspect. Vacuum hoses, coolant hoses, intercooler connectors. Budget on replacing all those, plus the timing belt, water pump, front and rear seals. The gearbox should be fine if it is not crunchy, but it will not tolerate significant upgrades in power for very long without wearing out the input shaft bearing. So if following advice to embiggen the motor, budget on adding a big box too. Ditto the brakes. Bigger motor = bigger brakes. The suspension could be in any state at all. If all original, then most rubber bushes will be crook and need poly replacements or entire arm replacements (to obtain adjustability). The front upper control arms are shit on R32s and the only workable aftermarket substitute is by GK-Tech. Those stays on the rear wing are stupid. Otherwise, go for it. It is very similar to the car that I have owned for the last 20 years and have done the entire list of upgrades above, and more, to.

Are you doing this without the freely available wiring diagrams in the workshop manual?