For '75, the SD455 was gone. The NHRA specs for the D-port 455 made it non-competitive. Don't remember ever reading about any Stock or SS car running a '75-'76 455.
The Birds still had front & rear similar to the '74 model. But, it was the 1st year of the "wrap-around" rear windshield, and there were park/turn lights in the grills, similar to those of the '74 GTO.
The 400 was still fairly competitive. Ryan Warter still runs the only one I know of, in a '75 Formy. He's won several big races, including the 2018 Northwest Nats. That was an All-Pontiac final, against Randi Lyn Shipp.
https://www.dragracecentral.com/DRCS...r2018#indextop
I've only known of one '76 Stocker. It was raced by Mike Morgan, for several years. He won the K/SA class at Indy, in 2014, running more than a sec under, in the final. Kevin Love owns the car now.
https://www.dragracecentral.com/DRCS...r2014#indextop
I got to wondering why so few guys had run a '75 or '76. A quick look at the NHRA engine specs, on the Class Racer Info site tells why. It's compression, or rather LACK thereof. That's why there have been lots of '74 & '77 400 Stockers & almost no '75 & '76 models. If a guy decided to build a '75 or '76 Pontiac Stocker, he'd be handicapping himself, by several hp. Just not a smart thing to do.
Anyhow, I'll post 8 pics of the '75 & it's wins, & one of the '76.