Yeah farm from what I have read it seems the 3" is the only way to go for stock. I have read all the reasons why anything bigger than 3 won't be beneficial (other than fit) on a stocker but I still have questions.
I just need to understand if ther is no point in going bigger than a 3" downpipe as the outlet is only 3 and any bigger won't allow anymore flow (this is the argument I have read). Then why bother going any bigger on the exhaust.
My though is that bigger allows for more volume of exhaust to escape where smaller has higher pressure creating more backpressure. My question would be, why not just go 4 right away and get that volume moving even if it is bigger than the outlet. Just like going from a 3" downpipe to a 5" exhaust it will open up room for more volume of exhaust.
This certainly digressed from the op, but valuable for me to learn anyway.
Oh yeah, if you 4"down were to fit a stock, I would be interested