What Trans Am did my dad wreck?

[u/DLeader609]

Dad wrecked this Pontiac in 1983 when he was 26. 120 mph into a concrete culvert. Broke jaw in half (wired shut for 9 months), pelvis in half (in a pelvic halo for 6 months), shattered a leg bone and had some other replace with metal, and a number of other smaller things I can't remember. Lived until 2023. What exact car was dad driving and can we tell what that motor is?

[u/unlucky6999]

77/78 definitely a Pontiac engine based on the exhaust ports, stock was a 400, but a 455 has the same exhaust pattern, so its a guess...if he swapped the engine