Haven't heard duals on a 4.7 so I don't know how they sound. I have a 2.5" single in 2.5" single out with a 3" tail pipe necked down to 2.5" at the muffler, side exit behind the rear wheel. Probably being a single plus the headers with the 3" tail make it sound quite a bit different from yours. Is yours the original 40 series? I've heard those can be pretty rough sounding.

 

Unless your racing and looking for every hp you can squeeze out just throw in a single in/dual out or single in/single out muffler. Most people add exhaust because they find the vibrations in their ear drums pleasing. Duals in this sense would also only be pleasing to your eyes (or if properly angled you can remind road irritants that you too enjoy scenic routes but would like not to be apart of them).

Without headers or true duals you're not going to see that much gain if any of the two I listed over the other. Running true duals is more expensive because you now have to buy two mufflers. By then, it'd make sense to use infamous exhaust scavenging "X pipe".

There's no argument needed because it's a known fact that a free flowing true dual setup will see added hp over y-pipe. Typically, that shifts your power band too. Retaining Y-pipe design will keep your low end torque. So if keeping low end torque is in your interest go with single exhaust or imitation duals b/c one isn't better over the other

 

Currently mine is the same size as the stock piping, didn't replace the y-pipe so there was no reason to go any bigger (I forget but I think the stock is 3" anyway). I think it gave it a bit more oomph but that could be the butt dyno effect . As for mpg, well with the way I drive I'm not the person to ask about anything increasing that, lol. Mine cost me under $150 out the door including buying the dual tip off ebay (well now it's over that but its because I cut the tip off, painted it black and had it welded back on). With a regular tip it should probably cost you right around that, I got a discount on the muffler for being a repeat customer and recommending friends to the local guy I used.

 

Just picked up a CB Vortex for $60. Now I got a Thanksgiving project. I'll let you all know how it turns out. Thanks for the help

 

Cherry Bomb FTW!!!!

 

So it would be 2.5 in and 2.5 out to match the stock set-up? I can change my order.

 

Ok, here is one more from the newb. And it is a 2.5in pipe, not 3in. my bad.

So, did you guys delete both resonators or just one. I guess that is personal preference as well.

 

Depends on the year truck ya have, they varied by year