Fox GEARS! 3:73's?

M

MustangOwner

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#1

• Jan 30, 2007

• #1

Hi, i was just wondering what would be the best gears for my car. All i do is drive on the street and highway. I only put about 3-4 thousland miles a summer on it. People go back and forth between 3:55's and 3:73's. I have heard there isn't much of a difference. And for gas mileage...well its a mustang. its not suppose to have good gas mileage ha. But i dont want some gears that are reving high as SH** when driving on the highway. thanks

 

M

mike93lx

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Jan 30, 2007

#2

• Jan 30, 2007

• #2

Do you ever take the car to the strip? auto? stick?

3.73's seem to be popular with people just doing street driving. If you want to maximize your drag performance, 4.10's would be something to consider. THey are what I'm putting in my car in a few weeks.

 

8

86bluecobra

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Dec 20, 2004

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#3

• Jan 30, 2007

• #3

Get the 3.73's. I have them. Great gear on a long trip you don't rev alot at highway speeds. Also it is a good gear at the track. get 3.73's. one thing to consider is that unless you change the gear out in the tranny you will not get your speedo 100% accurate with 3.73's.

 

f4fntm

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Oct 10, 2004

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Jan 31, 2007

#4

• Jan 31, 2007

• #4

A stick, according to Car(ugh)Domain.

You're currently running the OEM 2.73? 3.55 will be fine.

 

5.0 Nostalgia

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#5

• Jan 31, 2007

• #5

Either will be fine. I would recommend the 3.73's though. I have had both and there is not a really big difference in engine speed. As stated, if your car is a 91 and the transmission is original, you will not be able to get the speedo accurate with just the gear on the speed sensor. If that bothers you, you will have to either get the 3.55's or remove the tailshaft and change the internal gear.

 

Grn92LX

Fidanza Man!

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#6

• Jan 31, 2007

• #6

I'd do 4.10's.

I have 4.30's in my car and they don't rev high on the highway. Unless 2300-2700 is high I had 3.73's and they SUCKED with my combo.

 

ninety15.0

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#7

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It sounds like you have a stock HCI combo and bottom end...so i would not heed Grn92lx's advice...he has a wild HCI combo. Of course there are applications when 4.10's and numerically higher gears are required...but a stock headed/cammed car is not one of them. 3.73's are what i would go with...but they are as steep as you should go. First gear will be almost useless and second will be lightning quick as well. 3.55's will only show about 250 rpm difference from 3.73's and gas mileage will effectively be the same with either. i turn 2500 at 75mph with 3.73's and still pull 25+ mpg. If you have blower or nitrous plans for the future then i would go with the 3.55's but 3.73's are the best all around gear for 5-spd stangs. good luck

 

payupsucka

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Jan 31, 2007

#8

• Jan 31, 2007

• #8

i have 3 73's and i wish i went with 4 10's dont fear the gear

 

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bt15

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Oahu

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#9

• Jan 31, 2007

• #9

+1 for 3.73s

I have plenty of all gears in my 85 T-5 car with 3.73s and don't have any problems on the highway. I'm running a BG 650, Edelbrock Performer RPM, B-Cam and GT-40X aluminum heads - works perfectly with this combo.

 

C

C6AE

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Jan 31, 2007

#10

• Jan 31, 2007

• #10

I love my 3.73's
I'm gonna love 'em even more when I get the close ratio T5 in my coupe

 

M

MustangOwner

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#11

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• #11

Oh yeah my bad, its a t5. as of now there are no engine mods. but the future is h/c/i and kennebell. in 1991 the speedometer is still off even when you replace the speed sensor gear with the correct 3:73 tooth? why would it be any dif for the 3:55?

 

Black Sun 5.0

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#12

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I've been told it's pretty tough to keep your wheels on the ground with boost and any gear higher than 3.55. I've been wrestling with this decision for a while myself and, since I'll be installing a supercharger, will probably be sticking with the 3.55's. I'm sure there will be plenty here who will disagree.

 

D

DRock9

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#13

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• #13

Im looking for that info myself...

 

5.0 Nostalgia

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#14

• Jan 31, 2007

• #14

91FoxSaleenGTLX said:

Oh yeah my bad, its a t5. as of now there are no engine mods. but the future is h/c/i and kennebell. in 1991 the speedometer is still off even when you replace the speed sensor gear with the correct 3:73 tooth? why would it be any dif for the 3:55?

Click to expand...

A 23 tooth gear is the most you can get. 90 and up t5s came with an 8 tooth drive gear in the transmission. A 23 tooth gear in this trans will make your speedo accurate with 3.55s. Therefore, in order to correct if you have a lower gear (3.73's and up), you would have to replace the gear in the tailshaft with the 7 tooth gear that came in 89 and earlier t5s.

I am a little beat right now, if I messed up that explanation, someone please correct me.

 

1

11.50fox

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#15

• Jan 31, 2007

• #15

my car goes 11.50 with 373s and tremec. and does good on the hwy. also

 

M

MustangOwner

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#16

• Jan 31, 2007

• #16

Ok, well thanks alot for your help. I'm pretty sure im gonna go with the 3:55's. They will be a big jump from the stock 2:73's. I definetly want my speedometer right. I put my 18's on my car but i made it the same height as my old ponys so my speedo is right on. Also about how much does it cost to get somebody to put gears in your car? What do you gotta buy to install them other then the rack and pinion gear that is like 167.00 or so. 50resto has a big kit thats like 200 and some or something like that. Looks like alot more then i need to me. But im not a expert on rearends. All i didn't myself was put my new axles in.

 

onefstsnake

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Jan 31, 2007

#17

• Jan 31, 2007

• #17

I just got some 4.10's installed.

The difference between the 3.73's and 4.10's is 250rpm...

My next motor is going to be able to rev to 7k+ rpm so the 4.10 should be great.


I didnt think they made a 23t gear... I still need to buy a speedo gear for mine.

 

I

iwashmycar

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Apr 7, 2004

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Jan 31, 2007

#18

• Jan 31, 2007

• #18

3.73s are good. i got em and do about 300-350 miles/week

 

5.0 Nostalgia

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#19

• Jan 31, 2007

• #19

I would have a shop do the work. If they are not properly shimmed, the gears will whine and wear out prematurely. Depending on the condition of the rear, you may want to have everything rebuilt while it's all apart.

 

onefstsnake

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#20

• Jan 31, 2007

• #20

have them put in a B or C rebuild kit from Ford.
New bearings and seals sure puts the mind at ease. lol