Box into Main Panel

Spent most of the day trying to figure out how to get this box in place. Decided to put it right above the main panel since I'm running the conduit up the wall. Most people in the 'hood are running theirs just the opposite. However, they are going into the ground and running the wire to their pools or hot tubs.
















Here is another picture of the panel with the front plate off. You can see a 3/4" hole that has a lock ring installed. I was planning on using the hole right behind that one since it has a 1" opening. If I can get the wires throught the 3/4 hole I might do it.