[Jeff Lee]

I disagree. "Factory Type" infers seats from the factory and does not infer the seats must be from the body that surrounds them. NHRA is very specific when they want something specific and it would say something like this: "Seats must be for make, model and year produced". "Factory Type" in my opinion is something you would see from the OEM, not a Kirky as seen in SS.
As an example, the rule once read "radiator must be from same model" so guys with a '69 Camaro were running a 2002 Camaro radiator which is aluminum and lighter. The rule now reads "Radiator must be from same make, model, year" or words to that effect.
I say run your Cavalier seats unless NHRA tells you otherwise.