I would think the tubes are 304 but that flange sure seems to be 4xx. The added nickel in 3xx alloy is more rust-resistant and polishes up nice, and re-polishes up as good as new. But I'm not really aware of any performance-related issues with 409 (auto exhaust spec) or 439 (spec'd for cats); eg as far as the inside of the pipe/etc goes.

 

May i sugest some Remflex Gaskets to go with those? Lifetime warranty and they are awesome. Used them on my 96 which kept backing out header bolts (flowtech headers) and blowing through gaskets. The remflex gaskets are worth it.

http://catalog.remflex.com/MOPAR_Hea...t_p/rf6004.htm

 

something I came across in a header article...
Stainless Steel:Stainless steel exhaust headers do not have a coating. Instead, their resistance to rust and heat comes from the metal itself. There are two types of stainless steel used in performance headers: 409 and 304. The difference is that 304 has more chromium than 409, so it is stronger and is not as prone to corrosion. Both grades of stainless can bear high temperatures, but each type will lose its luster eventually. Stainless steel performance exhaust headers are ideal for mild and moderate street use, as well as for towing. For stainless steel, check out Dynatech, JBA Headers, DC Sport, Gibson or Borla headers.

 

I bought those exact headers. I had to grind down the flat brace to clear the spark plugs. Things also didn't line up too well but that's nothing a little flexing can't fix. Overall I am happy

 

See on mine the flange is the exact same size as the older header they are replacing...gaskets seem to line up perfect...
Did you buy them from the same seller?

 

I bought them through eBay Canada so yes a different seller but they look the exact same, to the position of the welds and all. It could be that I have a 2002 so the newer body style and the 5.9 why things didn't go as smooth as they should have..

 

Sorry for the grammar fail, I am on my phone and cannot edit posts

 

No that's not why. Your factory exhaust manifolds are the same as ours. They are just cheap parts. Many others have reported the same issues.

 

To make things a little smoother, make sure to align the downpipes and bolt them up while the headers are loose on the heads... I learnt that the hard way when nothing lined up ha!

 

Or it could be what I stated twice already.... there are more than one very similar type of generic headers being sold with slightly different specs...

Ebay is just an electric trading bay... they do not have their own brand ... I dislike that everyone makes assumptions on things bought there like it effects all products by all sellers...I'm specifically reviewing the ones for the eworld seller not others form other sellers...if I had those side by side I could do a comparison too...
what color gaskets did yours come with green silver or black? and is your flange where the down pipe attaches also polished or does it have a slight texture to it? what size is it? some use 2" and some 2.25" from the specs...
Plus again... I think most headers dont line up prefectly with everything... its just because these are no name they may get more blame. some might be bad yes..the point here is to weed out speculation.
To be fair my magnaflow sytem didnt line up perfectly with my pacesetters either....it believe there are lots of factors and everyones truck might have slight variations in where and how the pipes sit...I for one have a body lift and that certainly effects room under the hood.