Truth be told, I peaked at 1100 maybe once or twice since owning the truck and never moved anything more than 5000lbs. Think I was squeezing down the carpet on the way up the road to the ski slopes (no cooling fan either

). Intercooler is probably more of a concern if/when I get a moose pump. I am wondering if if there would be any MPG gains for more mild conditions like the 2-5 psi range where EGTs are normally 700 or less for me. The answer seems to be a yes or at least a maybe, from what I am reading.
Guess I am trying to justify the expense when in reality all I am thinking about is hunting down powerstrokes on the open road. Had a confirmed kill already on a 10% grade

. Should be possible to even the score if you had the higher fuel flow and intercooler that later PS engines came with from factory with.
So is there even a point in going with 3" plumbing? Seems to me like 2.5" should be plenty and easier to fit.