I had original keys made from the PHS docs. The code is on there and the dealer has to translate it and cut the key, if they have one. I had to buy keys from Ames first.
If you don't have the docs or the cylinder has already been changed, you can use a small drill bit to drill out the tumblers from the front and pull it out.
1967 GTO; Gulf Turquoise on Black, 4 speed bench
1967 Camaro ss/rs 350
1966 Chevelle SS 396
1970 Cevelle SS 396
1952 Chev 2 ton flat bed
1938 Chev coupe