Drivetrain 3:73s To 4:10s Is It Worth It On A '99 Gt Automatic?

Discussion in 'SN95 4.6L Mustang Tech' started by 99 FLA PONY GT, Apr 27, 2013.


  1. 99 FLA PONY GT

    99 FLA PONY GT Member

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    I have a 1999 MUSTANG GT with an automatic tranny. The car has just about all the bolt ons you can get. I took off the catalytic converters off & got MIL eliminators to trico the computer so my check engine light wouldn't come on & put in MAC long tube headers, an h-pipe & welded in Flowmasters. I had a Steeda tune/chip put in back in '99 or 2000 when I installed 3:73 gears...with the new gears my speedometer was off so I got the chip to adjust that & it also adjusted the shift points on my automatic tranny. Good mod & I had the car dynoed @ Steeda many miles & years ago & with all my mods...intake, pullies, exhaust, timing adjuster, cold air etc she pulled 244 to the rear wheels & a best of 14.1 @ Moroso. She consistantly ran 14.3s. Maybe if I was 50 lbs lighter I'd would of cracked into the 13s with a 13.9? :(
    Anyway, one Friday in early 2006 I got laid off from AT&T after nearly 21 yrs there. I was 2 months away from getting medical benefits for life so I was livid. I did what I always did on a Friday night & drove my PONY down to Davie, Florida for the weekly cruise-in @ the Tower Shoppes. After the show/night, I was still seething & I-95 was virtually empty up by Stuart so I said to myself-self let's see what this **** can do. I had the car up to 132 mph & I had to myself I better ease off the gas before I blow a tire & kill myself or get pulled over by FHP or a Deputy Sheriff & get arrested. I was pleasantly surprised by the speed & power the car had especially in the upper rpm range. My biggest concern switching from 3:73s to 4:10s is not reliving the bad experience I had when I installed 3:73 gears in my 1986 Cutlass Salon...the 2 door body style that looked like the Buick Grand National. That car was beautiful with those chrome rims & raised white letter tires, but a dog of a motor...307 V8 that produced 140 hp. With the 3:73s the ride was over @ 80mph...it was like the car had a governor on it. I just want to be able to hit 110 mph on the highway every once in a while without hitting that virtual brick wall.
    B) Is it really worth the difference from a 3:73?
    A) Does having 4:10s on an automatic '99 GT work well & can I go 110 mph without the car shaking & whining like a little ****. Hate feeling the governor feeling I had w/my Olds. Happy w/the 3:73s but if I can get more feel in the seat of my pants & the car still has plenty to go after hitting 110 mph
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  2. BlackenedSVT

    BlackenedSVT Active Member

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    I say NO. Stay with the 3.73s. If you want more oomph, go with a power adder. You will not
    feel a difference in the seat of your pants with that gear ratio change.
    #2
  3. 99 FLA PONY GT

    99 FLA PONY GT Member

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    Wish I had the money to get the "right" power adder....a brand new 420hp Coyote 5.0 motor!
    Damn Ford for not giving us GT owners any serious HP until 2011 with the reintroduction of the new 5.0. Ever since I got laid off I'm now making a third of what I used to make...can't afford a late model now so as an original owner of my '99 GT I keep it as nice as I can. I still love my new edge body style but I also love the late models with all that HP. The sad part is I had $10K in cash set aside in 2007 for a brand new Black California Special Convertible but once I got laid off I blew through that money in no time. :(
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  4. usaf_branham

    usaf_branham Member

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    *bs. i went from 4.10's to 3.73's because I put a blower on my car. the only reason i switched was because i was bouncing off the rev limiter by the time i went through the traps. if i could do that all over again, i would have left the 4.10's in the car and told my tuner to increase the rev limiter...

    the car was more fun with the 4.10's
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