Intresting results with factory 05 gt mufflers.

That's definately interesting. Can you describe the sound for us?

I guess I'm not too surprised because when driving behind my dads 06 GT, I can see nearly unrestricted to the front of the muffler. It isn't streight thru, but it is quite open. The other big difference, would be this muffler is tuned for the behind the axle mounting location on the 05+.