Technically most 2.0 litre engines will fit into a micra, doesnt mean you should try it if you cant figure it out :glare:, but the SR20DE is the obvious choice and has been sucessfully fitted to a good few over the years.
SR20DE is the obvious choice but as Frank's pointed out in the past a lot of projects have begun but the majority of which have been abandonend.
Main things to consider with the SR20 is custom driveshafts, engine mounts and how to mount the water pump (it scores the engine bay unless you move it or redesign your inner arch ) (Y)