Those headers that ARH has are Stainless Steel I think, They are pricey but good Quality, I was steering towards 1.3/4 stepped to 1.7/8, and I like the advise (Free) that
@GTX JOHN gave us Really appreciate that, he's very knowledgeable . I have a 400 ci Indy headed small block with SFT cam pushing 600HP on a street car and I feel that they would work great, Or even a 1.7/8 Race header from TTI, Presently it has hooker fenderwall headers that previous owner had and I would like to go with underchassis instead and cover up the holes on my Inner fenders, I like the look better with underchassis