I'm not sure why you crossed out your first answer. It is correct; the way to change between big and little endian packed IEEE floats is to use reverse:

    $ perl -le 'print unpack "H*", reverse pack "f", 440'
    43dc0000

    $ perl -le 'print unpack "H*",         pack "f", 440'
    0000dc43
[download]

--
John.