I would think without a vin list, and then being able to see what cars have what it may be hard to pinpoint exactly when early, mid and late occur. Production starts in Sept, and ends in late July early Aug? (I assume theres some shut down/change over time). I would say an April build would be mid production. I would consider June/July late production, JMO. I thought the only diff was between the early early low scoop and the later higher scoop, thinking that most 77 and 78 were the same.
