I don't think (correct me if I'm wrong) that the ifly has ARINC output, so you'd use the other serial port - not the second ARINC port - to connect it to the HS34. But beyond that - assuming that it has NMEA output that is compatible (this post suggests it should http://dynonavionics.com/cgi-bin/yabb2/YaBB.pl?num=1409845662), your setup should work.