1976 Trans/Am 455 Last one ?

[Donutblue]

My cousin is the original owner of a 1976 T/A with the 455, 4 spd. She is offering it to me at a good price. It has been sitting in her garage since 1986 with over 150000 family miles. When she ordered it,She knew Alex Mair GM of Pontiac division at the time and was told by him it was the "Last 455 off the line" that year. She has lots of paper work, but no documentation other than Mair and the dealer telling her that. I called Pontiac and they were unable to confirm that. Any suggestions on how I can get that information.