This might help: https://www.engine-codes.com/p2101_nissan.html
All parts are in stock that you may require.
Just drop me a PM if I can help further.
I would also get the battery checked.
The clutch release bearing is not turning when the clutch pedal is up.
It only starts to spin when you press the clutch pedal and the release bearing comes into contact with the clutch cover diaphragm.
I run a Kaaz 2 way in my track 350Z and it is superb.
I also have a spare Kaaz 2 way that has not done a lot of miles which will be for sale shortly.
I can set it up at 50% - 60% - 80% or 100% lock for you.
I run mine at 60%
It can come with or without side bearings.
If you want it all set up and installed into a pumpkin, then I can also do that for you so that all you have to do is install the complete diff unit to the car.
Just drop me a PM if of interest to you.