Well i talked to a aero exhaust representative and many people on this forum told me the same. I will lose back pressure causing low end torque loss. I want two tips out the back. I want to make a custom cat back set up. All stainless with stainless tips. How would you sset it up?
I think you've got a couple options.
1. You could run a y pipe (get a new one from magnaflow the stock one is restrictive) into a single in/ dual out muffler and then run the rest of the piping from the muffler out to dual tips in the back. This will mean you only need 1 at3030.
2. You could run an x or h pipe and then attach a single in/ single out muffler on either side (wherever you want) after the crossover. Then run from the muffler out the back for the duals. This will require 2 mufflers.
I don't think you'll be losing low end with either setup unless you go with piping that is too big. If you have no other mods on the truck and don't plan on doing anything else I would go with either 2 1/4" piping or 2 1/2" piping. If you plan on adding more to the truck (longtubes for example) I'd go with 2 1/2" to 3" piping but no bigger.
I can't say which setup will be louder or not s someone else may have to comment on that but I think those are your 2 best options. Just my opinion.