You could try something like this, you would need to know diff pin dimensions and find a similar diff as I doubt they sell a kit for the Micra.
The joys of owning a Micra, I was doing the usual pre event car spanner checks when I found yet more rust in one of the rear wheel arches on Saturday, meaning a couple of hours of metal work and welding.... :(
Yes it does, as for the best diff I prefer the quaife/suretrac Torsen type ones which are fit and forget (in terms of maintenance) and less harsh to drive with and less harsh on shafts / CV joints. If doing a lot of gravel then plated will be better but at cost of maintenance and shafts / CV's.
This has just appeared on ebay.... https://www.ebay.co.uk/itm/Nissan-Micra-K11-Rally-Race-Track-custom-hybrid-Inlet-Intake-Manifold/174069373192?fits=Model%3AMicra&hash=item288757d908:g:IXwAAOSwzQFdqdbY
The head came from Matt Humphris in a package of parts I bought from him, I don't think he did the head work but had it done by someone else.
The 1Ltr box is a good improvement with the 4.4 diff, the 4.92 is another big step up again (plus it is semi-helical so sounds ace).
The flywheel I...
Read my blog (car specs) to see what we run, engine made 126bhp when mapped by Fusion Motorsport. That was old engine which was standard used bottom end, so new/current engine should be about 130bhp.
Running the 4.92 final drive makes a real difference and worth it. http://www.mattendean.co.uk/