1. I currently have a Lightning style SI/DO (exit in front of rear wheel) Magnaflow and was thinking about cutting it and just have turndowns welded to the muffler.
Q: Will there be any audible difference?

2. I was also thinking about maybe going to a SI/SI muffler like the Dyno Max Bullet,round Magnaflow,or a Flow Master Super 44.
Q: Is there a big difference in sound compared to my normal setup and is there a down side going to a SI/SO on our 5.4L?

Thanks in advance!

 

1. Yes - a lot more drone inside the cab and more exhaust gases getting into the cab too.

2. I don't know.