Alan-

I'm thinking they are stainless. I used some extra fine steel wool on mine and shined them up pretty good. I found them on an AD truck, but I don't remember what year. I don know it was a '47-'53.

-Tim
'51 Chevy 3104 w/'56 235, 848 Head, HEI Dizzy, Corvette Cam, Split Manifold and Dual Carter YF's