The file name called it a Firebird Camaro rpo list but I saw diesel engines listed (Cummins 4BT ???)
I had a co worker back in the late 90's that worked in the oil fields of Kuwait and said he saw GMC pickups there owned by the contractors that had 4 cyl diesels in them he swore were factory installs. Doubted him then but its looks like he was right. And it seems they were 4BT's.