In Smokey’s book, I think he claimed something like 200 sets of the porcupine heads were cast.
Not sure how many had final maching operations done, but Chevy would have to have a good number of heads in the pipe line if they planned to run this head configuration in Trans Am. The rules to homologate parts for TA stated that the items had to be available to the public in sufficient quantities. So Chevy had to make a pretty good amount of Z race parts such as cross rams, big sway bars, 4 wheel disk, hoods etc.
TA rules allowed service parts but they had to be pre-approved by SCCA.