[MrStang18]

Hey, I'm looking for some help because I'm not very knowledgeable on the subject. I want to install either 3.73s or 4.10s gears on my V6 mustang but really sure of the difference between the two. In addition to it being my daily driver (I live in a suburban area with lots of stop lights) I also like to take it out on road tracks. Could some one help me figure out which would be better for me and give me the pros and cons of both.
Thanks alot, A fellow mustang lover

[Codeman]

well the general rule is 3.73s for manual transmissions, and 4.10s for autos. Also you may want to consider buying a Ford Racing 7.5" 28 Spline Traction - LOK Limited Slip Differential at AmericanMuscle.com - Free Shipping! and a Rear End Installation Kit at AmericanMuscle.com - Free Shipping!.

The t lok will allow both wheels to spin when you lose traction helping add traction to your vehicle, and the bearing kit is recommended for any vehicle over 40000 miles.

as far as the pros and cons. You could run the 4.10s in either it is just you will have to shift a lot, and you will lose mpgs on the highway darastically. The 4.10s would probably be better for your road racing because you would get in the higher rpms faster, if you have a manual. If you have an auto definately go 4.10s they are perfect for overdrive.

as far as the pros and cons really you will want to go 4.10s over 3.73s in the auto or you will not gain that much acceleration.
for the manual you will gain quite a bit acceleration with 3.73s, but you will gain greater acceleration with 4.10s. the downside to the 4.10s is your first gear will be really short and you will lose lots of highway mpgs. it is up to you. for road racing the 4.10s because i assume you are mostly in second if you have a manual.

[MrStang18]

I have a manual and I was actually looking in to getting a t lok or limited slip or whatever you wanna call it as well. The 3.73s probably sound better for me if theyre giving me a substancial acceleration increase with out ruining my mpgs. I'm not exactly mr money bags so paying for gas is important. Thanks alot man this really helped

[Codeman]

ya no problem. i have 3.73s to waiting to install them here soon. They will decrease the mpgs slightly but not near as much as the 4.10s. good luck with your car. and welcome to the forums.

[9986paulk]

Yea in the op's case it might not hurt his mpg as much or really even noticeably since he's in the city with a lot of stoplights. But yea, just a little more shifting with the 4.10s, though I think its at a little less than 35 mph for 1st gear.

[Ticket-Me-Yellow]

Heres what i gotta say, i have a manual and i had 4.10's and i loved them without the supercharger. I had pretty much basic bolt ons, but once i put the m112 on i noticed that i have to shift a lot faster. I havent ran through the gears yet but idk if im gonna like it. I no all i do right now when i hit it is spin in first so i might have to back down to 3.73's.

Pretty much manual + bolt ons + 4.10's = fine
manual + supercharger + 4.10 = not so fine

[Codeman]

Heres what i gotta say, i have a manual and i had 4.10's and i loved them without the supercharger. I had pretty much basic bolt ons, but once i put the m112 on i noticed that i have to shift a lot faster. I havent ran through the gears yet but idk if im gonna like it. I no all i do right now when i hit it is spin in first so i might have to back down to 3.73's. Pretty much manual + bolt ons + 4.10's = fine manual + supercharger + 4.10 = not so fine

ya i know that i would like the acceleration of the 4.10s but i do a lot of highway driving and i was hoping to procharge my car so i figured i would stick with 3.73s.

[Ticket-Me-Yellow]

Yea true. When i had the 4.10 without the supercharger it was fine on the highway

[ewells2420]

Originally Posted by Ticket-Me-Yellow Yea true. When i had the 4.10 without the supercharger it was fine on the highway

lol whats it like with the eaton ... im about to find out soon myself =P

[Codeman]

what were your rpms at on the highway at like 75? jc. with the 4.10s

[itschristorres8]

guys the difference in MPG between 3.73s and 4.10s is about 1/2-1mile per gallon.

i know that choice is a tough one but sadly its the truth....

not so bad

[JTs03v6]

I would not go any lower than 4.10 manual ot auto trans. My brothers 5spd had 4.10's with some spray. it was fun as hell to drive. I went 373 but want to install either 4.10's or 4.56 ratio.
btw... I did not loose any gas mileage going to 373's. 300miles to the tank before and after.

[Codeman]

ok thanks. i guess i will see on the 3.73s worst case scenario i just use them for a bit and then if i dont like them i will move onto 4.10s

[JTs03v6]

Originally Posted by Codeman ok thanks. i guess i will see on the 3.73s worst case scenario i just use them for a bit and then if i dont like them i will move onto 4.10s

Dont get me wrong...373 is a decent all round gear ratio. But if you want to do any racing and go with a centri like you want to, 4.10 is the sweet spot because they will put you in that power band quicker.

[Codeman]

you think even 4.10s with a manual and a centri blower?

[JTs03v6]

Originally Posted by Codeman you think even 4.10s with a manual and a centri blower?

yep. Especially with a centri. You need to get the rpms up to get in that power curve. By doing this you will have to run a good rear tire on the street and strip. I run nitto 555's on the street 275's and was running 555r 255 at the track with just 373 and could not hook for shit. Next season going with bias ply 26x10x15 slick for the track to compliment the new rear gears and stall converter.
Also will be doing some suspension work.

[MrMadMunky]

i have 3.73 with a tlok and i love it runs pretty good at the track as well

[Codeman]

alright well i will have to see how i like them. worst case scenario i just swap to the 410s later.

[pyschopath76]

hit them 4.10's up bro......promise you that you wont be sorry!!

[Codeman]

ok well maybe i will. i already have the 3.73s brand new with the tlok and bearing kit waiting to be installed in my car. i cant do it till summer it is too cold and i dont have a heated garage, so maybe i will just sell the 3.73s and buy the 4.10s not sure yet. i would love the 4.10s but it is just i drive 225 miles highway a week.