I've owned a blue '77 T/A that was a 403 Auto, a '78 black & gold 403 auto.
And I had a '79 white T/A that was a 400 4-speed with a worn out engine. The '79 400, with a worn out, smokey engine and probably a broken valve spring or two, was a faster car than either of those 403 / 180 HP POS's.
And a buddy had a '75 or '76 T/A 455 4-speed with A/C that was all stock. He bought it because it was the big engine and a 4-speed. Man, was that thing a pig! He didn't want to deal with making it fast so he didn't own it long.
Another buddy of mine worked at Mechum Pontiac in Glendale, AZ and he was in the paint shop and applied all the Macho T/A graphics. On slow days he put the headers on. By the time Mechum was done, you had a solid, low 14 second '77-'78 T/A (pontiac engine of course). I remember a a brown one (maybe an '80?) in the show-room that had full IMSA flares and a 350 SBC with a turbo (twin turbo?).
I guess because I graduated H.S in '78 and saw Smokey & the Bandit at the local drive-in, I'll always like those 3rd gen T/A's. I'd love to have any of the '70-'73 models. 4-speed mandatory of course! SD-455's will probably always be out of my budget.