When mounting the base for the T-250-H driftmaster, do you have to drill a hole in the center for the T bar rod to go in? I just ordered a set of these and I am trying to see how to mount them before I even get them. But I see that the rod mounts in the middle of the base, but it looks like the rod goes through the middle of the base to what I assume is a locking nut or something on the base.