3.55 or 3.73's?

[D's 91 stang gt]

Just wondering what gear to go with I have a few bolt on's nothing major and the car is a daily driver. I'm leaning towards 3.73's but I'm not sure just want some opinons. Also with what ever gear I go with how can I fix the speedometer so that it will read correctly?? oh yeah It's a five speed car
thanks

 

[IntenseBlue]

3.73s are what I'd go with. It's a red 21 tooth gear.

 

[kck6894]

I would go 3.73's also

 

[notchback]

unless your considering blower/turbo 3.5's shouldn't even be an option you look at.

you won't be happy.....3.73 or 4.10

 

[Fishhawk]

A lot of it depends on what kind of driving you do. There are times when I'm at the track I wish I was running the 3.73's. However, a couple runs down the highway, and seeing that I'm getting 22 MPG and I'm glad I went with the 3.55's.

 

[N8Miller]

the difference between the two listed gears is like 200-250 rpms..... just get the 3.73s.

 

[D's 91 stang gt]

thats great guys I think that I will go with the 3.73's. One more question once the gear is installed how do I fix the speedometer so that it will read correctly??

 

[srothfuss]

the difference between the two listed gears is like 200-250 rpms..... just get the 3.73s.

My car is as stock as they come. With the T-5 and 3.73's I turn around 2500 RPM down the highway @ 70 - 75 MPH. I can still get 300 miles out of 1 tank of gas so the gears might have helped my MPG a little. The step up to 3.73's from 2.73's will be awsome and won't hurt your daliy driving ability. All it will do, is make getting traction a problem.

 

[Paul Perreca]

i have 3.55 (came w/ my car) they feel really good, but everyone says 3.73 are the way to go, i guess it wouldnt be worth it for me to step up to 73s from 55s -
Paul Perreca

 

[89lxsport50]

My car is as stock as they come. With the T-5 and 3.73's I turn around 2500 RPM down the highway @ 70 - 75 MPH. I can still get 300 miles out of 1 tank of gas so the gears might have helped my MPG a little. The step up to 3.73's from 2.73's will be awsome and won't hurt your daliy driving ability. All it will do, is make getting traction a problem.

If you can't get traction with 3.73's then it would stand to reason that 3.55's might have a performance advantage off the line, provided they allow you to hook better. Just a thought.

 

[srothfuss]

If you can't get traction with 3.73's then it would stand to reason that 3.55's might have a performance advantage off the line, provided they allow you to hook better. Just a thought.

It's not too much of a problem in my vert... I wasnt' meaning that it was horrible, I was only sugguesting that it's much easier to burn off some of the tread if you were feeling so inclinded..

 

[89budget50]

definetly go with the 3.73's and then get the red 21 tooth speedo gear from ford, mounts on the side of the transmission and speedo will be off by maybe 2 or 3 mph at different speeds. You won't be dissappointed with the 3.73's!!

 

[Fishhawk]

thats great guys I think that I will go with the 3.73's. One more question once the gear is installed how do I fix the speedometer so that it will read correctly??

You can order the speedo driven gear from Ford, Mustangs Unlimited, 5.0 Resto, etc. You'll need the red 21 tooth. Thats if you have a 5-speed. The AOD uses an entirely different gear. Find where the speedo cable goes into your trans. There will be one bolt holding the cable in with a clip. If the cable has never been pulled before it will give you a little resistance. Don't be afraid to give it a good tug. The speedo gear is on the end of the cable and held on with a slip on clip. Once you see it, it will be obvious to you.

 

[Grn92LX]

Out of those 2 choices, 3.73 is the best bet. You want the white 23t gear. You can order it online or from a jeep dealer. Its not a perfect match but it works. A red 21t would be for tremec's or older t5's like pre 89. Even with the white 23t gear your speedo will still be off but w/o changing the drive gear thats as best as your gonna get.

 

[Mysterio]

My car is as stock as they come. With the T-5 and 3.73's I turn around 2500 RPM down the highway @ 70 - 75 MPH. I can still get 300 miles out of 1 tank of gas so the gears might have helped my MPG a little. The step up to 3.73's from 2.73's will be awsome and won't hurt your daliy driving ability. All it will do, is make getting traction a problem.

Wow i'm sold.. I run at 2000-2100 rpms @ 80 mph on the highway with stock gears in my car. If it's only going to rise it another ~500 rpm then 3.73's are definetly what i'm going with I was wondering that as 3.73's are one of my next mods but wasn't sure how badly highway driving would be.

 

[89CopCoupe]

3.73's in a daily driver

3.55's in a daily driver

73's are fun if you like to shift as often as a truckdriver
-For '90 and newer trannys they don't make a gear for this r&p
-1st gear (3.35) is too short for a street engine and you might as well take off in 2nd
-5th gear (.68) is too low for added highway gas mileage

55's are fun if you prefer the best of both worlds
-The shifts are a little faster, but you can actually use 1st gear
-5th gear lowers rpms by 250-300 rpms which promotes better fuel economy and allows the car to have a little better top speed.
-They make a speedo gear for this ratio

Ford themselves recommend 3.55's with a 5sp and 3.73's with an AOD ... who you gonna trust? Ford, me or everyone else

My '90 AOD has 73's and I'm gonna swap in a new FRPP 3.55 diff...
When I do, you can have the speedo calibrator I have to run to get an accurate reading

 

[5spd GT]

A difference of 200rpm is more than some are making it out to be. You can notice a difference...

Either gear is a good gear...I wouldn't go any steeper with a daily driver.

 

[1991GreeNLX]

go with 4:10 if your all motor go to steeda.com they have all the gears their to recal your speedometer

 

[Mean86GT]

i got 3.55s and they are great on the highway and rodding around town but when i go to the track i wished i had 4.10s

 

[89CopCoupe]

i got 3.55s and they are great on the highway and rodding around town but when i go to the track i wished i had 4.10s

Exactly, but for the one trip to the track each year I could never justify it.