Is this a good choice of a motor to swap into a 240 Z.I have seen this done before to a 510 .

I see no reason why it wouldn't be a good choice, although I have not seen one done in a Z-car yet. I'm not sure why though. I would be interested in finding out if anyone has done it and what it takes to do the swap.

Yes you can put it in. Check out HybridZ.org for more inf on the swap.