Ron,
I have a 07 Mustang with a tune. About 320 RWHP. It has a 3.55 rear. I'm looking at a G* GT right now and have test driven a couple of them.
My opinion is unless you are talking about a more exotic Mustang, the Mustang is going to take the G8 out of the hole, cause the G8 only has a 2.92 gear. But the G8 is going to take top end.
I tried keeping up with one on the expressway one day, and he was gone.
Now as to which one. I think its going to depend on what you other needs are. I love the Mustang. If I could afford to keep it, I would. I drive it every day rain, shine or snow. The problem is my gold clubs or hockey bag share the front seat with me. The G8 has a big enough trunk to put em in.
