1977 Blazer

[noco-k5]

I am thinking about buying a 1977 Blazer. It's a California truck and I'm located in Colorado. Does anyone know what emissions equipment it would have had originally. I've done a search on this forum and others and there are a lot of different opinions. It only has to pass a two speed idle test here, but I'm more concerned about the visual inspection. Some things I've read said 77's had minimal emissions while others indicate they have smog pumps, cats, etc. Any clarification would be appreciated.