Ok,
I've got an 05 Screw 4x4 w/ the 5.4 3v & 3.73LS. In the next few weeks I'm gonna be adding e-fans, AF1 3.5" & custom tunes....well, I'll be ordering the tunes. I also want to add a maggie exiting from infront of the rear tire and might be adding some long tube headers in the future. So would I be gaining or loosing power if I have them do a true dual into the DI/DO maggie w/ the built in X or should I just get a SI/DO muffler?

Thanks,
Myren

P.S. I searched but didn't find what I was looking for.

 

You should call your tuner and ask them the exact same question. "They" are the ones doing the tuning and if they know what they are doing and are a reputable tuner then they should be able to give you a definitative answer..

 

I'll do that. I was just wondering what ya'lls input was.

Thanks.
Myren