I am about to pull the trigger and change up my exhaust. I currently have a SI/DO Flowmaster on the truck and do not care for it. I am wanting to go with Magnaflow 2.5 in and 2.5 out but have a couple questions.

Truck = 2009 4.6L V8

If I run a SI/SO with a Y pipe which muffler would you recommend? 4X16 or 4X18? I want deep tone with the least amount of drone.

I would really like to run true duals with an X pipe but after having the Flowmaster I am hesitant because I don't want to deal with the drone. Which muffler would be best for this setup? 5X18?

Also, if you could give me a part number it would help considering it seems like Magnaflow has a ton of mufflers.

 

 

I read the exhaust guide and decided to pick a direct through muffler for performance and sound. I bought the Magnaflow 12259 with 3" SI/SO all the way through. Really like the deep low sound and the price was good.

Two months later still like the sound, but can not put up with the drone at 1800-2000 RPM (cruising speed range). My truck is a 5.4L and I'm not sure if drone would be similar on your truck with the same muffler. Recently I bought the Corsa dB Performance (24310) to replace it. It's still a direct through, sounds great on youtube and they guarranty no drone in the cabin with their RSC technology. Once I return from a current business trip it will be installed and hopefully it will meet my expectations.