R-12
R-134 Refrigrant.
134 freon
Freon is R12. Your 1997 Chevy uses R134 Refrigerant.
R134a
R134A
1994 Ford Explorers came with 1lb 8oz (24oz) of R134A freon.
134a
R134a
depends on the engine size and the transmission type.
Freon should be R134a.
Says it on the oil cap.