That is an impressive title bestowed upon Justin L Abbott: Zip Resident Engineer Product Development and R&D Manager (shown on the CF right at the bottom of this page).
There are three 1969-1982 upper air dams that were never supplied by GM. I created them for phonies like David Walker & John Wayne Walker. There are no GM blueprints, because GM never made them. Apparently a previous Resident Engineer was confused & searched at DocRebuild. You are being used up just like all the other Zip employees that have come and gone from Tim Pope, to Tom C. to Michael McWilliams.