Called the tech line at Flowmaster last nite and they gave me a part number for one of the just released exhaust systems for the New 2004 F150, Part Number 17394, dual side exhaust system. Exits 1 each behind rear tires, stock location. Tech said just got released and should be available in a few weeks from most outlets. List Price $547, I've have mine on order thru wholesale outlet for $308. They are using the Super 40 muffler, with quite a bit of growl... they said.. I'll wait and see once I receive the system. Flowmaster tech indicated on there dyno runs +5-7% hp = 15-21 HP gain, no torque numbers given, sounds like a lot for a muffler, however it is going from a single to dual system. Just the exhaust note would be nice, truck is far to quite.

 

I agree with you regarding better exhaust sound and the increase in HP is a little wishful; but I am curious, besides the cost, why would you go from a stainless steel system to a galvanized one?

 

As I said the truck is to quite. It really needs a little bit of exhaust note. As far as stainless goes, my trucks see around 5000 miles a year and are garaged. The last 2 Ford's I've had, one for 9 years and one for 5 years both had Flowmaster systems from the beginning. I've had several Flowmaster systems on other car's and trucks and have never wore one out yet. I would also have the additional HP if any as a bonus. Works for me...