whats the difference between the MBRP cool duals t-304 and t409's there both stainless besides the $$ whats the difference is one louder or better than the other??

304 is high polish and more nickle content IIRC. the 304 should not rust at all....the 409 will probably get some surface rust on it.

ob ijr - your recollection is correct . . . from a practical point of view, the only difference is cosmetic (shiny, bright "show" quality vs. every day driving) & cost -$$$$ - either one should out-last the life of the truck - or - so I was told by MBRP - IIRC . . .

409 will rust.304 will last much longer and is a higher grade of stainless.

Thats what i was thinking but as far as performance there both the same...

There would be no difference in performance between grades.