There aren't any CA smog legal performance cams made for the 78 302. But how does the smog machine know if I have a mild cam installed. I mean if it idles were it's supposed to and the timing is set to factory, how would it know. If it's tuned properly it should burn clean, right.
The smog machine doesn't know anything but what comes out of the tailpipe. If your performance cam has characteristics that cause increased emissions (over stock), then you are in trouble. I'm thinking about valve closing overlap, etc. Just higher lift by itself should not be a poblem. You'll just have to try it.
What are you doing about the visual inspection? Do you have to have the stock carb, etc?
Using an oversized carb (more fuel) might cause problems due to higher hydrocarbon emissions.
Some high performance items can cause increased increased NOX emissions.
What's been done to the engine other than the cam?
New cats with air injection might help the tailpipe situation.
As my sig shows I'm currently running a Holley 600 but will have to reinstall the EGR system (I have the Performer 302 manifold with EGR) and stock 2-bbl for the test. Other than the cam I have ignition upgrades like MSD-6 with Blaster coil with new ditributor (stock) and MSD 8.5 wires. I have the Hooker headers but haven't installed them yet, and won't until after I pass smog. And, split the exhaust into duals after the Cat.