Print head for Epson 4900/7900

Can anyone tell me if the printheads for Epson 4900 and 7900 are interchangeable? They are physically identical.

While they are the same print-head at the nozzle-end, they have different control boards and fittings. Sadly they are not interchangeable (I tried back in the day so I can tell you this from painful experience lol).