Where I live we can pretty much fit any engine and still get it registered. Obviously you have restrictions, but I was wondering you'd probably be able to fit either a QG16DE or GA16DE(if you would like to keep the block iron), and still get it legal.

A friend of mine has an Almera with the GA16DE motor, which he fitted with a turbo, I built the manifold for him. Anyway, motor was completely standard and not even the CR was dropped. He pumped around 0.8bar into it, running extra injector and methanol injection for higher than 0.4) and was making 163kw and 256nm with it. It was totally reliable and the only thing that kept on giving up the fight was the gearbox.

I was looking at it and thought that if I ever had to build another Datsun, that was what would go into it. Nothing else.