looking at headers, what a good quality metal??

[KKell83]

Yeah I've been looking on e-bay, it seems like there headers are working out fine with the 7m.. But what should I look for metal wise, as in I found two headers but they have different stainless steal quality...
SUS321 or SUS304... Whats better?
Thanks Ken...

Should I look somewhere else?

 

[IJ.]

321 by far!

 

[figgie]

SUS321

of course money no object you would want one of the InConel alloys for that