QX80 is the same body and exhaust wise. just some added software features, a new 5.6 emblem.
the stock exhaust is quite beefy but the muff and resonator are a bit restrictive. if you want instant gratification at a good price, do what i did; chop off the muff and resonator.
i am not a big fan of dual exhausts on this particular engine because some back pressure is a good thing for it. having a dual exhaust compromises that a bit in my opinion.
i of course am not an exhaust pro but I did stay at a holiday inn express last night..