Well one huge difference would be the lack of a radar, which is a heck of a limitation for an A-A combat role...
That's why the sidewinder fit was just a "boresighted" thing - point the aeroplane at the target and hope the missile's seaker head can acquire what you're looking at rather than an integrated solution in which the aeroplane's radar hands over a specific target track to the missile's seeker system before launch.
PDR