I have done my comparison shopping and listened to dozens of sound clips.... finally decided on the Dynomax Ultra Flo for my '03 4.7 liter. Good sound, good price.

Now, according to Advance Auto, model 17220 is a direct fit, but according to JC Whitney it will not fit. Anybody have any details on fitment?




http://shop.advanceautoparts.com/web...983%7CL3*15335

 

I put the Dynomax 17296 ultra flo on mine, similar to what you are looking at except its round and not welded at all the seams. I personally have had bad luck with a stainless exhaust that was welded then rusted out at the welds, I am not sure if it was low grade stainless that couldn't take the heat of welding or the wrong wire was used but I try to avoid welded. Stock is 2.5 inch pipe these mufflers are 3" in and out. Stock is offset on one end but center to center will fit and work fine. The muffler will be too short to just replace the muffler compared to the stock so you would have to use an extension pipe if you plan on just replacing the muffler. I suggest you replace everything from the cat back as you will be going from 2.5 to 3 inches.

This is what I installed on mine, it was indeed a direct fit on a 2001 5.9 rt and cost me about $250 in parts. I don't think you can go cat back much cheaper than that.

WALKER Part # 17296 Dynomax ultra flo muffler
WALKER Part # 52154 intermediate pipe attaches to cat.
WALKER Part # 55005 Tail pipe

 

Thanks for the advice, but my budget will only allow for the muffler.... can't afford the cat-back system.

Any ideas or recommendations, y'all?

Flowmaster 40 is an option in my price range, but they're louder than what I am looking for. Dynomax Ultra Flo is what I want, but can't find the right fit.

 

I think the part #17513 is the one you are looking for in Ultraflo welded or #17289 in non welded. These would both have 2.5 inch in and out with 1 offset. The length might be a little long as my memory fails but these are both listed as 25" long. I think stock was 23" but you can measure yours to be sure. A couple of inches xtra can be accommodated. I put the address below for the Dynomax ultraflo catalog in case you don't have it. Lots of good specs and such for sizing.

http://www.dynomax.com/downloads/pro...ed_muffler.pdf

 

Wow, thanks so much for posting that! I spent an hour searching the internet for the right fit...now I know the exact one I need. Thanks, man.

 

Thrush welded!