yes the stock standard exhaust for the 3.4 is an absolute joke!
even just a high flow cat and a 2.5" mandrel bend exhaust will see much improve ment
not many place do the extractors cos such they have to fab up a y piece to connect the extractors to the zorst
altho if money aint a worry go for it,
i was gunna get extractors with twin zorsts for mine but lift and tyres need to come first