I think I understand what you're saying, but if you mean you plan to run two pipes from the manifolds out to the tail, that still means you'll be buying twice as much pipe (from manifold to back bumper, cuz the pipe comes in 8' sticks...and you typically will need a couple sticks per pipe) compared to if you went single 2.5" from a 2 into 1 just past the manifold...or am I still not thinking clearly here?