Old flash with Dslr, would I be silly to consider putting it on my camera?

[Regwah]

A Sunpak 2000dz, from what I have googled people are saying the trigger voltage they have measured is between 3 - 4.5 volts. I use a Canon 500d the hotshoe limit is apparently 6 volts.
Also what do the settings on the four position slide switch mean?
http://images.google.com.au/imgres?imgurl=http://imagehost.vendio.com/bin/imageserver.x/00000000/kiler/ebay17803.JPG&imgrefurl=http://www.flickr.com/groups/strobist/discuss/72157603904953666/&usg=__6DcjRdPgZtQ41bS4XuBAHUPBdp8=&h=480&w=640&sz=69&hl=en&start=3&sig2=xZTLOlbG85UdygUqsf5XHw&um=1&tbnid=vSE6RvCo2BKu3M:&tbnh=103&tbnw=137&prev=/images%3Fq%3DSunpak%2B2000dz%26hl%3Den%26safe%3Doff%26sa%3DN%26um%3D1&ei=Gq8dS6_wFp32tAPh_72hCg

 

[New York Diva Part II]

I say try it out and see.. but no matter what your photography is always beautiful.. i need another bird pic for my wallpaper screen.

 

[New York Diva Part II]

I say try it out and see.. but no matter what your photography is always beautiful.. i need another bird pic for my wallpaper screen.