Newbie help with gears and exhaust

[sporter]

Hey whats up? I just have a few newbie ??? for all of you.As of now I have a CAI , Magnaflow axle backs , and a Dibailo Sport tuner on a 05 GT.I want to purchase a x or h section with or without cats , my ??? is which will work better?I know that there is a chance of my computer throwing a code without cats but other than that it should be fine.I will also have a charger on it within a few months and i am not sure if I need those cats or not.Also my car is a 5 speed , would 3.73 gears make much of a diffrence up from the 3.55s in it now?If anyone is running 4.10s what is there rps at highway speeds?
thanks guys....
Steve

[Brent]

I dont have a 05 or even a GT but I have 4.10 gears in my 96 Automatic Mustang and at 80MPH I turn about 3300 rpms I believe.

[SpectorV]

I would keep the cats, they get very loud, and illegal with out them~ check your local laws and see how enforced they are as well.

Gears are great. I would go 4.10s with an auto and 3.73 with a manual, but some like 4.10s with a manual~ expect a loss in gas on the highway and it to stay the same in the city~

[bbunt302]

I'd go with the 4.10s. 05's come with 3.55s stock, so the upgrade to 3.73s would be nearly negligible. If you do indeed want to upgrade, I would definitely do the 4.10s. Otherwise, you may end up thinking you wasted your money.

[wiarumas]

he's from canada so the no cats thing might be legal up there?

if you want a loud ass motha take the cats off. if you dont want to be "wake the neighbors" loud, keep em on. as for H or X i dont think there is any difference other than sound. if you have the money to throw around id get X, but either or doesnt really matter (i think).

as for the gears, 3.73 would be a good acceleration, 4.10s would be crazy (but not in a bad way). i agree with both spectorv and bbunt.. usually, in the past, 3.73s are a good choice for manual transmissions and 4.10s are a good choice for autos. however, bbunt mentioned that the 05s have a higher gear ratio than previous years so 3.73 might be not that huge of an improvement (you would definitely notice it though). my personal opinion is 4.10s.. my reasoning is go big or go home haha.

[Rick0636]

I had 3.73s in the stock rear end of my 99 GT, when I traded for the 03 Cobra IRS it had 3.55s, there was only a tiny difference, and I believe my gas mileage might have improved a bit. I was happy with the trade off. I loved the IRS rear end too. Handled great. Personally I dont' think I would want to change the gear ratio in my 06 v6, might like a traction lock differential though, everything I have done and plan to do to my 06 will help gas mileage, not hurt it one bit.