Wow, there's so much conflicting info out there on how to install kext files! I'm a total n00b and still trying to understand how it all fits together.
I copied /Extra/GeneralExtensions/IO80211Family.kext to my desktop and edited Contents/PlugIns/AppleAirPortBrcm4311.kext/Contents/Info.plist to add string pci1434,4727 to the IONameMatch array. What do I do next to "load" the updated kext file? I tried clicking the Install Kexts button in the OSx86 Tools Utility, but the ~/Desktop/IO80211Family.kext file is greyed out when I try to select it.
I don't know if it will work, but it seems worth a shot. 4727 is the device ID that I see when I generate a PCI Device/Vendor ID list using the OSx86 Tools Utility, even though the sticker on the card says BCM94313HMG2L.