OK, I had this exact problem when I bought my 1981 with the same engine....

You should have a bracket that holds the thing as well as a smaller one in back, here are
mine:





Go to a junkyard and get yourself a smog pump, here's what I ended up with:




It installs mainly on the bigger bracket, the one in back is just to hold it in place. The belt
(not installed here) attaches to a pulley on the alternator, the hose connects to the check
valve that screws into the intake manifold (pic in earlier post):



You have a non-catalyst F350 so this pump doesn't really do anything useful but it's still
required that it be there.

BTW these are Federal laws....

Clean Air Act | US EPA
Transportation and Air Quality | US EPA
http://www.epa.gov/oms/regs/fuels/cff/memo-1a.txt