The problems with chrome plating many parts is the small crevices where parts some together, like the collector area of a header. You just can't throw plating all the way into those areas and they will eventually rust. That's where stainless steel works great, particularly if the tubes are polished before they are welded into a header.

The normal process is to copper, nickel, then chrome plate, in that order. Rusted parts are sometimes salvaged with a heavy copper plating, followed by sanding and polishing to remove the rust pits, then all three platings are done. It's the copper that enhances rust protection and a heavy layer of nickel that really enhances the shine. If the nickel solution is off, the parts won't look good. Properly done, the parts should look just about as shiny before plating as afterward. If you see an area where the color transitions from silver to more golden, the more golden color is nickel showing in an area where the chrome didn't throw.

FWIW, I've got polished stainless steel exhaust manifolds and pipe on my car. It didn't take long for the manifolds to turn a golden color, even with the internals sprayed with a coating from Eastwood that's supposed to help prevent the discoloration.