Find headers with y-pipe. Y-pipe is the choke point. If makeing own get the 2 to 1 y extension. Maybe a new cat but 2.5 pipe on the Durango is stainless and will flow enough air. According to my muffler shop if I want more sound, increase tailpipe diameter. Other than that your choice of muffler has been debated time and time again here. Flowmaster, Magnaflow and glasspack. I posted my two trucks with Flowmaster last week so look back a page.

 

I don't know why but I can't find your videos. And I've got a flowmaster muffler on mne too I've got the super 10 series on it I love it

 

for better sound and more flow. like ivy said fin yourself a decent set of headers. tubular stainless, ebay has sets for under 150. good quality. they give a deeper more rumbly sound. and many different manufacturers make 2.5" and 3" y pipes and "direct fit" catalitic converters so match your sizes. if your willing to spend the extra money go for the 3" and stainless tubing does give you a much better sound as compared to galvinized piping. also the stainless will never rust out!!!!!!!!!!!!! ever!!!!!!!
so in my oppinion. go with the 3" stainless cat and muffler and tailpipe, and the stainless headers!!!!!!!!!!!!

 

https://dodgeforum.com/forum/1st-gen...und-bytes.html
Here is the link. I just got back so I will do a come and go video on both trucks.