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Discussion Starter #1
I have a mostly stock '03 GT vert 5-speed. Most people have told me that putting a set of 3.73's in it is a must. My only concern is that this is also my daily drive. I drive mostly around town each day. Will I lose a lot in gas mileage or wear and tear on the car (not including tires because I know that is up to me and my driving style)? Any comments on brand, price, and help in these areas mentioned above would be helpful. Thanks
 

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i was going through that prob with 390s or 373s but i am going to go with 373s in the long run is a safer bet since i am daily drive to....
 

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3.73's will make a night and day difference in your car. Especially a heavy convertable. Highway driving should not suffer much with overdrive, you will actually be able to use it more and not lug the motor down on hills like with the stock gears.
 

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Belive it or not, my mpg and top speed actually went up when I went with 3.73's. ( I drive 70 to 80 miles aday )
 

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I like my 3.90s. A little more "oomph" than 3.73, but not pure race oriented as 4.10s or 4.30s. My gas mileage hasn't dropped.
 

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Discussion Starter #6
If I go with 3.73's, will I need to get a tuner or have it tuned for the speedometer and tach? Also, same question for 3.9's. My next mod will definately be gears, but I don't have the cash for both gears and a tuner. What is my best bet?
 

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I'd go with a set of gears first then find a good tuner like a diablo or sct. your speedo will be off a little bit but not much.
 

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I got a diablo tuner, and i love it, i got it first then gears... well i am in process of getting gears (had to buy some tires first) but yea you will be pleased with a diablo predator
 

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ibeeskeef said:
If I go with 3.73's, will I need to get a tuner or have it tuned for the speedometer and tach? Also, same question for 3.9's. My next mod will definately be gears, but I don't have the cash for both gears and a tuner. What is my best bet?
I put in the gears a couple of months ago and just got the tuner this week. My speedo was off about 20% (75mph actual was about 92mph indicated.)
Also clicks your odometer over at the same increased rate.
 

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Discussion Starter #10
so if i put gears in then i need to get a tuner on it as soon as possible or i am going to be pretty far off with the speedometer and roll up miles i am actually not driving? That does not sound like a good thing. What size gears did you put in?
 

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landgod did 390s, i am going with 373s for more conservative plus i might wanan spray something into my car later =)

i know someone at ford that car tune your speedo after gears for some money $ but id get the tuner because even with out gears it will make your car faster and more responsive..

i dropped from 14.3 to 13.9 with my tuner and my offroad xpipe combo..
 

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ibeeskeef said:
so if i put gears in then i need to get a tuner on it as soon as possible or i am going to be pretty far off with the speedometer and roll up miles i am actually not driving? That does not sound like a good thing. What size gears did you put in?
Yeah, your mileage and indicated speed will be higher than what you are actually doing. So if you do a lot of miles, it's gonna rack em up pretty quick. Myself, I only do about 8000 miles a year on my Stang so I wasn't too concerned about a few extra miles on the clock.

For the speedo error, until you get a speedcal or tuner, just use a speed-to-RPM calculator and make yourself a cheat sheet to stick on your dash. Seriously -- it sounds corny, but it's better than a ticket.
 
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