Well it looks like the senders are made specifically for Ricks. They recommend 1 inch minimum clearance.
http://www.wemausa.com/specifications/ssidweb.htm Mine is 1.25. She said they could make me one from scratch but it would cost out the nose. It would need to be 6.5 inches. It's understandable to need some clearance but over an inch seems like alot. Especially since the float is is really about 1.75 inches off the floor since the clearance is measured from the bottom of the collar.