I'm running 800cc's sard's on an emanage blue on a blitz ecu which is tuned for 550's and I would say that's about the max. Getting it to idle right took me three days.
Assuming your car is a street car;
If you consider running 1000cc's on an emanage blue on a stock ecu that will be a little over the edge, the blue can adjust injectors up to 150%, so on a stock ecu that would be max. 925cc's. You will need to have an idle of about 1200rpm to keep it running, and won't be able to pass any emission test.
What fuel are you gonna run? If you only will be using pumpgas, 720cc are all you will need, bigger is useless on a 3ltr engine, let alone a 2.5ltr.