Does anyone know which are the best headers and catalytic converters for a 98 ck1500 with a vortec 350, and be Cali legal?

 

I'd guess your best bet to be a set of SMOG legal shorties. Reason I say that is because if I'm not mistaken in California the cats have to remain in their stock location. FWIW I've heard some decent things about the Edelbrock TES system. Although I think the general consensus will be that shorties just aren't worth the money/effort for the little gain.