I have a 13 f150 with the 5.0 that I recently purchased. I researched cat back exhausts and didn't see any that I thought were with the money. So to youtube I went looking for which one sounded the best. I loved the sound of the straight piped trucks. So I had a local exhaust shop build and install a set of 3" duals. It's 3" from ahead of where the resonator was to a y pipe the dual to the back of the truck. It sounds like the youtube videos I watched except one exception. Sounds great on cold starts and at low rpm take offs and at cruising speeds. But when you really get into it you can really hear whooshing sound more than screaming exhaust. Hope you can understand my hillbilly lingo. My question is this. Do you think that noise is related to the size of pipe used or something else?? Thanks guys