You're about to find out.
Maybe you should ask questions like this BEFORE you go off and order new stuff if there is any question.
What would you do if someone said, "no, that won't work"? What about if someone said, "yes that will work fine"? Would it change your actions either way?
You already ordered the card, so you might as well plug it in when you get it and find out yourself. Too late either way.
Outside of the video card issue, you know that motherboard will support Pentium 3 processors (it may take a BIOS update, though). You can always grab a slotket and a Coppermine 550-650 for about $200. No need to ditch any 440BX motherboard right now. They're still the fastest and most stable motherboard available after 2 or 3 years of service.
BP6, Celermine 566@850, 320meg, CL TNT2U 175/220
BP6, P3-700@770 (for now), 320mb, eVGA MX Plus (dual CRT), waiting for VIVO module