GTSBoy

Well, it's supposed to be snug. The reason it won't go onto the input shaft is probably that it's cocked in the crank a little, from not being snug. Would have to guess that the end of your crank is worn out. which is no good thing, because, it may or may not be concentric. If concentric, you might get away with adding some thickness to the OD of the bush (wrapping it in shim perhaps, or building it up with hot melt metal glue and turning it back down. But if it is not concentric then that will only destroy the front bearing on the gearbox (and possibly the rear bearing on the crank). Don't know what to suggest you do about it.

The RB26 ECUs want to see 2x AFMs, 2xEGO. You have 1 of each. The things you have to do to make it work are not a lot of fun. Funnily enough, you're not the first person to want to do this. You could google and find out what others have had to do.

Consult exists for a reason.

Yup, stock ECU + nistune will be a much easier process than bodging a 26 PFC to work on a 20.

I'm damn sure that if someone just put a 7670 or 7163 onto an RB26 they would have exactly the ~300rwkW screamer that you all pray for. Ceramic coating and judicious use of heat shielding is a triviality that I won't even bother to go into.

And the answer is never twins.

You talking about the half moon? I would always put some hylomar or red juice or something similar, especially up at the corners. Just realised the half moon is the wrong end. Statement remains the same though.

No, you cannot fill from the shifter unless you know pretty much exactly how much oil to put in it. It has to be full to the bottom of the fill hole. The best way to do that.....is from the fill hole. Yes, you can get oil into the box through the shifter. But, see above.

There is no dipstick on a manual gearbox.

You have asked too many questions there. I would have to type about 2000 words to even get close. Some answers. Yes, they are all R200s. Well, all except for the very puniest versions, which you will never see. NA R32/3 have 3x2 stubs and open diffs. Turbo R32/3 have 5x1 stubs and viscous LSDs, which suck donkey jizz and may as well be open. Stubs from open diffs will not fit VLSDs because the VLSDs have funky unequal length stub axles, which is even more annoying than the fact that they are pathetic open wheeling shitball diffs. GTRs have things that are not compatible with your stuff, so forget about anything with 6x1 for now. S chassis cars have 3x2 stubs regardless of whether they are open or VLSD. The housings are otherwise the same as the equivalent r chassis car (so S13 like R32, S14 like R33). So unequal length 3x2 stubs out of S13 VLSD will fit R chassis VLSD. You will need to open the diff you have to find out what is inside. Could be anything. Could be original, or could have been f**ked with by someone. 5 bolt CVs are marginally stronger than 3x2 bolt CVs. In reality, 3x2 bolters are not even really CV joints, they are tripod joints and so not as good from the point of view of Constant Velocity. But they are not massively weaker than the real ones. I've had S14 driveshafts in my R32 with ~190rwkW for many years. They are fine.

It don't get much simpler than that there.

90% chance you cooked it and blew headgasket which has pushed various fluids various places where they shouldn't have gone. It's getting harder to find good 2nd hand engines these days, thanks to all the wankers who've treated them as if they were disposable all these years. A rebuild is starting to look more like the path people will have to take in the future.

Not sure why you want to specify inconel. If I were spending money on a GTR's turbos, I'd be going EFR, 100%.

The options for where the oil is coming from are innumerable. Diagnosing this without taking it apart, across the internet, is not going to be possible. Could be leaking from the oil pump gasket. You might have damage on the front of the block where the idler bolt is - which wouldn't normally be a suspect except for how your engine died last time. Needs at least partial dismantlery to find it.

You can also buy a box that goes in the antenna line (ie, the car's antenna plugs into it and then you plug the box into the head unit's antenna input) and it subtracts X MHz from the signal and effectively scales back all the local stations so they tune in on the Jap frequency range. It's what we all did in the 90s.

Not rebuilding the bottom end on a REALLY OLD engine is not always the right move when you're talking about headwork and big cams. There's no point in talking about porting and big cams unless planning on lots of boost and big revs. Massive boost + cast pistons not always good bedfellows. 270° cams on an RB20 = lag for days, boost from 4500 up to 9000+. I'd be thinking about new rods and/or rod prep, ARP rod bolts, forged pistons. At the least. Probably worth considering the oil pump situation too. Otherwise, it is fairly common to see RB20s run about 260-270rwkW without much preparation and run for a few years before popping.

It's far from ideal where it is. They really need to be placed right over the top of the turbo flange area.

I can't tell you about R33 stuff specifically. I can tell you that I only know for sure that the small plug works on R32s. Given that the HICAS systems on these cars are not the same, you should not assume it also works on R33s. And yes, on an R32 it's effectively a disabler for HICAS because the HICAS rack is self locking when it is in fault.

Of course....the driveshaftshop.com replacements (at approx. 1 million Pacific Pesos!!!) use not flanged inner CVs and an adapter ring onto the 5 or 6 bolt diff axle flanges. This would obviously be an option to anyone getting something customed up. If there were much stronger CVs that you wanted to use that didn't mate up - just adapt them. Easiest done with new custom shafts too, so the total length can be set right.

Um....why not set it to something, and see if it runs too hot or too cold and then adjust as per normal engineering practice?

https://xforce.com.au/product/vmk51-250/

Nope. As in, I don't know of any. I'd be reasonably confident that you could talk to any diff/rear end specialist that does hi-po stuff and they could probably source/make new axles that would be made from stronger materials or perhaps have some pixie dust waved over them. I don't know if there's anything other than the Nissan CVs available.

Fuel pump dead/dying or power supply to it dodgy, per trident's suggestion.

There were a lot of NA Skylines, Cefiros, etc made with RB25DEs in them. There are many of these boxes still available in Japan. If you need one, don't be trying to look in the USA, where there will be almost none. Try looking at the source. Consider using Jesse Streeter or one of the other buying & shipping agents who live over there to get you one.

Fair enough. But it doesn't change the fact that you have broader options for original source of your gearbox.