Even in 1983? Those kind of issues are still fought today. Those restrictions exist for a very specific reason, and its to ensure that key artist are credited upfront--kind of ego-centric if you think about it, but the whole concept of screen credit is somewhat ego-centric, and not unreasonable. Coppola i may not have belonged to the DGA at the time he made Godfather, though i could be mistaken. I think the DGA's main beef with Lucas was that he broke a fairly substantial rule for such a major motion picture, and the artists who gave him all his wealth were not properly credited according to union regulations. Back in 1977 head credits were a big deal--in fact, at that time it wasn't uncommon for films to have all the credits at the head. This in fact is how films were initially made--all of the credits that you see nowadays at the end of the film appeared at the beginning, and once the actual story of the film ended it simply faded to black with a copyright symbol instead of the lengthy scrolling credits at the end like today. In the 70's, the head credits first began to be truncated, and you had a long head credit sequence that usually credit the major artists and then at the end you had a more exhaustive sequence. Today this rule is much looser, and most films have only a brief opening credit sequence compared to the pre-1980's films-- i guess this is an effect of the so-called MTV generation, refusing to sit through three minutes of credits and instead wanting immediate action, and so the credits are almost all saved for the end. Its not so much a big deal now, although there still are still issues with films that omit opening credits completely, but in 1977 it was very radical.