hi im new around here just downgraded kinda from my 2011 and 2013 raptors to my new used 08 f250 5.4. i rely wanted a 6.4 but oh well thats besides the point.

the truck came with a gibson duel aftermarket exhaust... and well its soooooo quite. im use to turndowns on the raptors and i ran my old 06 150 off the cats with nothing there.

so what i need to no is what size pipe is the stock piping thats going in to this after market muffler? im just going to cut out the muffler and toss in a y and straight pipe it.

 

If memory serves me right Ford went back to all 3" exhaust for the 5.4l and 6.8l SDs in 08'.