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I am not trying to bash JBA or any other company. There is a difference between 409 and 304, and there is a difference when you run 2 1/2 in tubing into one muffler and then have two pipes coming out.

A true dual exhaust on a v-8 or v-6 is two independent lines, from exhaust manifolds back to where it exits the undercarriage of the truck. That is all I stated, and yes there is a lot of companies that use 409 and there custermers are happy.

The info I posted on the difference between 304 and 409 is of the internet, not my opinion.

I am glad you are happy with JBA, we have done a lot of joint ventures in the past in R&D and talk shop all the time. They make a great header system and a nice exhaust system.

And again I am glad you are happy with it.

I keep seeing 'ZOOMERS' on here 'not bashing' the competition but trying to relay that his product is far superior. Being a mechanical engineer his comparisons on 304 and 409 were interesting. I wanted to let everyone know what was 'really' going on between the two metals and why the magnetic vs. non-magnetic. First off, I'm not sure why your muffler being magnetic or not really matters. Who is going to put refrigerator magnets on their exhaust?

Zoomers, I'm not saying anything you said was wrong I just want to clarify some things. 409SS is a ferritic stainless vs. the 304 which is an austenitic stainless. The reason 409 is magnetic is due to it's 'higher' carbon content (0.12% C for 409 vs. 0.03% C for 304). These are rough percentages but they must contain less than that in order to classify as austenitic or ferritic. 304 is only more expensive because of it's high nickel and chromium contents. That's all.

Both have excellent corrosion resistance and it is true that the austenitic stainless is a more corrosion resistant material. But......409 has been chosen for exhaust systems by auto manufacturers due to it's strength against heat. And what happens to exhausts?......THEY GET VERY HOT.

When 304 gets VERY HOT it undergos sensitization. That means the chromium depletes the interior of the grain structure and will cause the steel to corrode very easily.

This is in no way knocking Zoomers. I'm sure they have a good product but saying that 304 is far better than 409 is incorrect.
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