slvrbllt77

i have a 04 gt and it's not performing the way i remember. everyone is telling me i should replace my gears with either 3.55 or 3.73. what should i do?

69MustangCoupe393cid

Is it not running right or just not fast enough for you? If its just to slow do 4.30s. I got 4.10s and I wish I went more. They are no where near as bad as anyone says. Hell you might have the .62 od gear in your car which would make it even better than mine. I dd my car and my gas mileage has hardly changed if at all. It's a completely different car now and so much more fun to drive. Btw get carbon clutch packs too, they're grabby as hell, just be careful in rain.

cliffyk

An '04 would definitely have the 0.062:1 5th gear, it was introduced in the early 2002 MY.

However as to the OP's concern, please further explain "not performing the way i remember". "Remember" as compared to what, had you not driven it for a while? What mods do you have, a dead stock '04 GT is a bit of a dog--215 to 220 rwHP at best, with a pretty anemic mid-range...

slvrbllt77

You're probably right. I had a 95 5.0 in 02 and that was faster. I think maybe the previous owner didn't take good care of it. As for mods...none. A friend of mine said that in 04 there was no one to compete with so Ford didn't make the stang very fast. Thanks for letting me know.

slvrbllt77

It's throwing a lot of codes, like PCM relearn, cleared codes, and things of that nature. It just doesn't have good acceleration. I was told that it's not a good idea to do any upgrades to it until I get those codes fixed. Short of getting a new PCM, I have no idea how to clear it and make it relearn. Any ideas?

budders

you should list the codes its throwing, or you can google the code and search for solutions. it might just be an o2 sensor, mass air flow sensor, ect.

uberstang1

4.10s

slvrbllt77

I was told that anything higher than 3.55 will destroy my gas mileage and put strain on my engine if I don't bore the motor and tranny. Is that true?

slvrbllt77

Thanks for the info guys. I took it to ford to get the diagnostics done and they told me no codes were thrown. They said that when I put the cats back on it went back through the drive cycle and cleared the codes. That's fixed but damn...the thing's still slower than previous years. Guess for didn't care when they made the 04. Well thanks anyway.

uberstang1

Engine boring has nothing to due with engine longevity with or without gears, you cant "bore" a transmission, who ever told you that is lacking automotive knowledge.