I have the 4.6l 2004 F-150. The stock exhaust system was two headers=> two cats=> two-into-one pipe=> SUPER long and quiet muffler=> one output pipe.

The first thing that I did to the truck was a custom exhaust system by ProMax in Washington .

Cat-back 2.25" dual pipes with two Flowmaster 40 DeltaFlow mufflers with 2.25" inner and 3" outer wall bezzeled stainless tips. Looks great under the rear bumper and the sound is amazing. Since my wife will drive the truck and we use it for long trips, I chose the DeltaFlow 40s for the lowered cabin noise. But, even at highway speeds, you know u have flowmasters. The idle souns is intense and with a gentle rev of the engine, they roar!

 

I was wondering the same thing - Crash_Edwards btw it looks sick!

 

I posted these before, but here they are again since you asked
my mods are in my Sig

2 Runs @ W.O.T.

0-40 nice and easy

EDIT Heres the orig post. Clicky

 

Video and Sound MagnaFlow Exhaust

 

I know nothing about installing Magnaflows or Flowmasters, so what does/should each one cost approximately for parts/installation? I was leaning toward the Flowmaster @ Midas, but I don't know if I should trust them or not. It was about $125, I think. But now I see Magnaflows may be better?

Can you get the tailpipes in black? Or do they all come in chrome?

 

I've had a Flowmaster on my truck since new and have no complaints. Originally put a 50 series Deltaflow on to replace the factory muffler. Recently upgraded to a 50 series SUV with DI/SO using dual 2 1/2" inlets and single 3" outlet. This got rid of the restrictive factory Y-pipe. Again, I'm happy with the performance and sound. 50 series are not near as noisy as the 40's.

 

Here, try these.

Driveway windows up

Driveway windows down

0-60 windows up

1/4 mile windows up

1/4 mile windows down

Driveway at tailpipe

Driveway 20ft back

Takeoff

Driveby

 

Wow that sounds loud for a magnaflow SIDO catback. Is that what it really is?

If so, can you hear it in the cab when you're not on full throttle?

 

Cant here it at all in cab at stops, but full throttle sounds sweet. Not as loud than a Flowmaster. SIDO it is.

 

I had a magnaflow, was very disappointed with it, for a 3" tip you'd think it would be louder, so I switched to Flowmaster, had the super40 with dual 3" out the side, loved it but I kept hearing a rattle in the muffler so I had it switched and about 3 months later heard the rattle again. So now I have Billy Boat, a ton louder then magnaflow and flowmaster. I was very impressed with the sound and the performance.

here's the billy boat sound off of the website.
http://www.bbexhaust.com/FordF150.mov