Pics of killswitch on 70-76 darts!

here is a switch that is on sale at a local parts outfit around me...does the amperage on it seem to be enough? do you guys think i should run something with more amp output?
http://www.taylorvertex.com/Products/pdfs/taylorcatalog37.pdf

I also hear of guys using battery disconnet switches from forklift part warehouses because they are the exact same thing...anyone ever heard of this before?