magnaflow is good. but expensive if u want great sound and good performance gain go to a flowmaster super 40 or super 44 but if u want loud as hell go with the flowmaster super 10 or flowmaster outlaw. there are many choices u can make i like flowmaster but dont think thats all u can do.. go on youtube and type in some muffler names like flowmaster,magnaflow,thrush,dynomax,cherrybomb,bassani,slp loudmouth,raven,mellowtone, im sure theres more i just ran out lol. if u like the sound try and type ur truck in the search bar like 2003 dodge 5.9 flowmaster super 40 and see wut comes up check out my channel on youtube/dodge2289 i have a few vids of my truck when i had a magnaflow,flowmaster 40,and now a flowmaster super 10