Muffler Size
Is there a relation between muffler's length and power performance of the car/truck?
From what i can tell you want to run a single muffler on a 420 horse truck .The 13" 40 series FLOWDISASTER muffler is good for sound but not flow. Your best bet would be a magnaflow muffler they sound good and are strait through flow.Best choice to free up some exhaust flow.
John
The Magnaflow mufflers are available in a wide variety of lengths. They actually neck out (to a larger diameter) when the pipe goes into the muffler. It is a straight through design. The longer mufflers will absorb more of the sound.
I have heard the same about Flowmasters - good sound, poor performance.
I just feel that the one I have got some back pressure at WOT.


