Thanks for your input. I think the above quote from 78TA.com provides the answer to my question. I also found these production numbers on 78TA.com which is really interesting:
1978 Model Manual Automatic Total
Firebird ** ** 32,671
Esprit ** ** 36,926
Formula ** ** 24,346
Trans Am 400 (L78) 0 57,035 **
Trans Am 403 (L80) 0 8,969 8,969
Trans Am 400 (W72) 10,889* 61,147* 72,081*
Y82 Trans Am 400 (L78) 0 ** **
Y82 Trans Am 400 (W72) 489 2,856 3,345
Here are some pics of my projects.
Y84 Trans Am 400 (L78) 0 68 **
Y84 Trans Am 403 (L80) 0 210 210
Y84 Trans Am 400 (W72) 20 68 88
Y88 Trans Am 400 (L78) 0 6,519 **
Y88 Trans Am 403 (L80) 0 880 880
Y88 Trans Am 400 (W72) 1,267 6,519 7,768