1976-1980 Chevy trucks smog exempt in California S.B.1239

[slotard]

In California, there's no regular inspection of any sort for '75 and older. If you want to do an engine swap, the engine can't be any older than the vehicle, and must be from the same vehicle type (can't put a truck engine in a car). You also need to use all the emissions equipment on the new engine. In theory this applies to '75 and older as well, but most people just figure they won't get caught (and very few people do).

If I put a 6.0 in my C20, which I think had a smog pump as the only piece of emissions equipment, I'd need to use the cats that came with it, the intake (not just manifold) that came with it, and so on. In order to change anything, it has to be parts approved by the state. Even though a 6.0 with a big cam and no cats is probably way cleaner than my current 350, it wouldn't be legal (but odds of getting caught are low).

Yes, the e-Rod swaps are smog legal as long as you use all the emissions stuff that comes with them. My impression is that evap is built into the ecu on most modern vehicles, so you need to get that working in those cases, but the e-Rod doesn't have anything for that which makes it easier.