In my opinion, it all depends on how you define the word "year".
Do you mean, the actual year in which a tractor went down the assembly line OR the model year of the tractor? Those are two different things.
Essentially, I don't disagree with Boomer because tractors for the model year 1983 were certainly built in 1983 as well as in the latter part of 1982. If you go by the model year, then my answer would be that the 1983's were the final year of the straight hood design and 1984 was the beginning of the bulged hood and that was also the year of the Black Frame models.