In the Bronx, Arthur Avenue is still overwhelmingly Italian.
In Brooklyn, Bensonhurst is still Italian and Carroll Gardens is also overwhelmingly Italian with a heavy mob influence (Frank "Punchy" Illiano and Albert "Kid Blast" Gallo seem to run the neighborhood like a fiefdom for the Genovese Family).
In Staten Island, Todt Hill is a residential community where many Italian-Americans and mobsters have historically lived.
In Queens, Whitestone (specifically Malba) is heavily Italian.
I live in the Bronx, and Arthur Ave is not "overwhelmingly" Italian, there are tons of Mexicans/ some blacks and college students who have moved into the area. There are still Italian restaurants there though... I was there a few months ago.