SR20DET will drop nicely in it, its a 2.0L turbo lump and can be found on eBay for about £1000
Yes, a SR20DE engine can fit into a Nissan 100NX. This can be done properly with some minor modification involved.
Nissan's GA16DE engine as fitted to 100NX, Primera, Almera, Sunny and likely others.
Yes, darn near any engine can fit into any car with the right fabrications. Sadly, it would take a TON of modifications to have this done. The B13 SER engine code is a SR20DE, which was never offered in a B12. I believe it has been done, but again, lots of modification. Go to srforum.com for all the info on that SR20 engine, what it comes in, what it can be put in, and if it can be put in. Good luck.
Whether or not a march fuel gauge will fit a B13 tank depends on the size of the march gauge. You should be able to find a march gauge that will fit on a B13 tank.
Yes.
if the year of the car is the same, then it should fit. before 92 and aftr 92 were two different fittings so have a check. i have a pulsar gtir steering on my 1.4 and it wrks and fits fine. so if your car is post 92, then the steering should come from a post 92 car also. other cars that also fit include the primera, 100nx, terrano and 100nx. although the primera sits a bit close to the column stalks.
No
If it is the same engine (the I4 or V6)
Yes it will fit in but it will not bolt up to transmission
YES
Yes a rb20det will fit
no