I have a 97 f-150 supercab, 4.6L. I want to put duals on but I can't decide on exhaust size, probably just doing cat back but I don't want to have to creap through town. Any suggestions. I was thinking a Y pipe off the cat with 2 1/4 pipe to 3 in tips? I know there's probably a thread on this but I can't find one.

 

https://www.f150forum.com/f11/exhaus...re-myth-78102/

 

As I have learned size makes a world of difference. Too big and it'll hurt, too little same thing. 2 1/4 or 2 1/2 should be fine. Personally I would do 2 1/2 if you are gonna go through the trouble of doing it at all. Since you don't want it too loud flowmasters are usually not too loud. I have 2 1/2" in and 3" out on my side pipe with a 2 chamber so it's pretty loud. With duals, 3 chambers, and full exhaust it shouldn't be crazy loud. Or you could do a "hush power" muffler...