I order a new exhaust manifold an it came in today. I could weld better than this. The mounting surface on both ends are bowed. So far no response from seller.

What the?!? Might help others if you posted where it came from.

Royal exhaust on Ebay.
They are going to except return.

That's really shoddy. Glad they're taking it back.

I think I bought a used cat/manifold on here. They're illegal to sell used, but I found a user that had one

IMO the R53/R50 manifold should be recalled, they all crack in the same spot, the metal is tin can thin

yikes