Is the shroud from Classic Industries a GM part or reproduction? It has the same part number as the GM shroud.
https://www.classicindustries.com/firebird/parts/10011265.html
I would call and ask if it is a GM part or a repo. Why buy the repo when the original GM part is still avalible.
ALL the shrouds for the 70-81 firebirds with a Pontiac engine will interchange. Maybe 75 and up have the inspection cut out and a sq hole in the top to mount an overflow bottle. The GM one has the cutout and the hole and looks like the one in the pic from Classic.