Can you find a picture of the spout on the internet so that we can see what kind of spout it is? There are different kinds of faucet spouts and they fasten to the faucet body differently.
If you can go to Price Phister's web site and enter the model number of your spout in the search engine in the top right corner of their home page. If you find your spout, just copy the URL of the web page and post it in here.
Alternatively, if you can find a picture of your spout, just right click on the picture and then click on "Properties". Then put the mouse cursor at the beginning of the Address/URL and press the left mouse button and drag to highlight the entire URL. With the URL highlighted (and only the URL), press Control c to copy the URL to the clipboard. Then come in here and click on the postcard icon. In the URL entry line, press Control v to paste the URL into the entry line. Then click the OK button.