/System/Library/CoreServices/Finder.app/Contents/Resources/English.lproj/InfoPlist.strings
You need to convert the file from binary to XML, using this Terminal command:
sudo plutil -convert xml1 /System/Library/CoreServices/Finder.app/Contents/Resources/English.lproj/InfoPlist.strings
sudo vi /System/Library/CoreServices/Finder.app/Contents/Resources/English.lproj/InfoPlist.strings
[raw2] <key>Folder</key> [/raw2] [raw2] <string>Folder</string> [/raw2]
[raw2] <key>Folder</key> [/raw2] [raw2] <string> Folder</string> [/raw2]
sudo plutil -convert binary1 /System/Library/CoreServices/Finder.app/Contents/Resources/English.lproj/InfoPlist.string
[crarko adds: I haven't tested this one. As always, make a backup copy of the file before making changes, and be aware this may cause code signing issues.]