Does anyone live in california that has a 76 to 78 280z have a header and still pass smog?

Headers will pass smog as long as they don't interfere with smog equipment.

Generally the answer is "No" on the visual unless it has a EO order number for the header.

Recently I went through this with my 76 Fairlady Z. It had a header with a fitting modified to go to the EGR. The smog shop did not accept it.

After putting on a stock exhaust setup I found a conversion diagram showing what was done on mine to be legal. Now I do not know how much of a fight it would have been with the shop over that diagram. To late now because it has a stock exhaust manifold.

My Z was run through a Federalization and emissions process to get it registered in the U.S. and California.

Thanks for the answers guy's.