I am sure some will work, but most I think you will need to rebuild. I am not sure what your objectives are, if its generic pentesting kind of work I really think long term you will be happier just running Kali in a VM.
That way you can just download the latest version when you need it rather than trying to keep all those tools up to date. The unfortunate reality is so much of that stuff is just not written to be especially portable and its not packaged up to built with make and autoconf.
Even stuff like metasploit pretty much ships with its own Ruby and Java binaries an just installs everything in its own folder up /opt sharing nothing with the rest of the system because no sane disto would use compatible versions of that stuff.
If all you want is metasploit, nmap, and stuff than you could install that directly to Slackware: http://slackbuilds.org/repository/14...rch=metasploit
But if you are after the whole tool box so to speak; its just to much work to make it all work happily on Slackware or any other desktop/server Linux distribution.