Anyone know the Pylon Base Diameters?

I have a 1984 Prostar 190 (Stars and Stripes) and would like to figure out what the pylon diameter is at the base in order to buy an extended pole with the proper inside diameter. Can anyone help me out? I did post in the old forum but thought I would re-post here hoping to get more response. My boat is a 7hr drive from me, making it difficult to find out.

Also, in order to install an extended pylon it looks as though I will have to remove the wing that holds the safety net. Has anyone removed their wing? Is this a difficult task?

Thanks,

Tyler