Does doing this net any performance improvement? Would it make a difference with x-type, h-type, stock type? What combinations of baffle sizes work well? Does this offer any benefit over a 2-1 (other than dual look)?

Thanks

 

Strictly speaking a 2-1-2 is a 2-into-1, but with twin outlets! A 2-into-1 will probably give better results, simply down to being aftermarket and not having to comply with EPA regulations. I can't see much point in messing with baffles etc when there are excellent complete systems available, which will give known results.

 

Rush varries the baffle sizes to balance the flow out a little better when using stock headers. Whether or not i makes a difference i have no clue. I hated my rush exhaust i had on my 2016 king.