Well looks like if it has the 400 there were 6528 Automatics & 1267 4-speeds, if it's the 403 there were 880 automatics.
1978 production numbers per
http://www.iwaynet.net/~gl&lisk/1978ta.html :
Model Engine RPO VIN Code Manaul Automatic
Trans Am 400 L78 Z 6,777 57,035
Trans Am T/A 6.6 W72 Z 4,112 4,139
Trans Am 403 L80 K 8,969
Total Trans Am 81,032
Trans Am SE (Y82-Black) 400 ? Z 489 2,856
Trans Am SE (Y84-Black) 400 ? Z 20 68
Trans Am SE (Y84-Black) 403 L80 K 210
Trans Am SE (Gold) 400 ? Z 1,267 6,529
Trans Am SE (Gold) 403 L80 K 880
Total Trans Am SE - 12,319
Total Production 93,351