What Alan describes (and displays very nicely on his website) is what is also shown in drawings in the Factory Assembly Manual (Section: 1; Sheet 17; and Section 1; Sheet 20.00).
Many people buy a kit from Chevy Duty (good price - good quality). The two kits that I bought had a copy of a copy of a copy of a drawing of the weatherstrip in the opposite orientation than that shown in the Factory Assembly Manual.
I installed the weatherstrip as described by Alan (and the Factory Assembly Manual) and had no problems.
Tim
