SO what do you guys thikn the 4.6 3v will put out with a K & N filter and a aftermarket exhaust? What about with headers added?
Well if it uses the same airbox, K&N is going to have to pull a part from their 'Heavy Equipment' division (Damn that thing is big). I think to add any benefit the whole airbox and inlet tube (which includes the installed hydrocarbon filter) will have to go. As far as after market exhaust, it appears the GT has a fairly decent exhaust from the start (2.5 inch piping all the way and very few bends). The manifolds look almost like unequal shorty headers in a solid cast piece. I really don't think the GT is going to free up that much HP in the exhaust area unless you remove the catalytic converters.
About the only thing you can do to gain any HP via, the exhaust is to weld in an X pipe crossover in place of the factory H and put on different mufflers. I don't think that it will be worth the time and money to replace anything else.
