Inner rocker line up

[85cehvy4x4]

Ok im confused about how this inner rocker goes on the truck. http://forum.73-87chevytrucks.com/smforum/index.php?topic=5661.0 I looked at this here, went out and looked at my truck, and it just made me even more confused. Now on that first picture on the link that flange thing on the left side(the first one thats circled) does that go underneath the floor pan, which would then make the flange on the right side sit underneath the seat hump? OR is the first flange part of the floor, making that 2nd one part of the seat hump; meaning that I cut out an outline of that piece and weld it in or is it made to be welded underneath? Any advice would be really appreciated.

[Captkaos]

It goes behind the rocker and under the floorpan.  You can see it here:

[85cehvy4x4]

Ahh ok yeah I kind of see it in that picture thanks. My floor pan rust through a little bit on the very edge where it meets with the rocker, so I am going to fabricate a piece of sheet metal to weld into that spot(its only like a 3.5-4 inch spot on that edge below the main part of the floor) so that first flange is going to be welded underneath the floor pan correct?