[davepl]

Almost certainly just cast iron, but of course they rust in the first weeks. I used an Eastwood product, and POR-15 and others make similar. Haven't fired it yet, but from those I spoke to it'll stay looking like that for quite a while, and you can touch it up as needed.

I glass-beaded the heck out of them first to remove whatever rust I could, though a chemical dip in rust converter might have worked better. I also blasted a ton of carbon out of the insides, which surprised me. Not that manifolds flow great even when new, but these were really loaded up!