'79 Limited edition blackbird GT question

My friend is looking at a '79 limited edition blackbird GT. Blackbird, not firebird. As far as I can tell it's based off of the Sunbird, but I'm not sure. I think it had a 305 before it was replaced with a hi po 350 by some kids. it's black with a false shaker hood, and gold door decals saying blackbird gt. plaque on the dash says 30 out of 500. i dont know if it's a limited editino factory model or from an eftermarket builder. if anyone has any information on this car it would be most appreciated if you'd share. I've looked everywhere and found nothing. thanks alot.

Hey!!! I hope its not to late...

I have information for your buddy with the blackbird...

he needs to contact me or go to www.v8monza.com and select h-body talk. Ask for info at that message board...all the monza/vega/sunbird/skyhawk/starfire 1971-1980 experts are there.