2003 4.6 Rear end gears

Bottom line, your friend is an idiot and you should not longer take automotive advice from him. I have 3.73's in my car, it NEEDS more gear. I want to go 4.30's but plan on some spray so I too will likely go 3.90s (possibly 4.10's if I decided to stay n/a)


When it comes to Mod motors, DON'T FEAR THE GEAR! :D
 
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Your friend must not want you to beat him. Anyways if you are staying N/A go with at least 3.73s. I have 3.73s right now and I'm switching to 4.10s. Whatever you do don't go with 3.55s unless going with roots style blower.
 
I like the stock 3.27's. In 5 years of driving my '03 GT, i never once had the desrire to change them.

I have 3.73's in my 5.0, and hate them. I'm debating switching to 3.27's in that as well.
 
Damn. Excuse my English. I respect all u guys opinion and prolly go with 3.90 only because it seems to be right in the middle. Only problem is Ford Racin does not make it but Motive gears does. But Motive is a great choice cause I had them in my 95. Love that combination. Thanks again for your input. Money will be well spent wisely :) .


if you plan on installing cams like you said a lot of them require 3:73's or steeper.

I have 3:73's installed in my car and wish i went with 4:10's. I probably will switch to 4:10's when I go to a 31 spline rear end

I think you will be happy with the 3:90's
 
I like the stock 3.27's. In 5 years of driving my '03 GT, i never once had the desrire to change them.

I have 3.73's in my 5.0, and hate them. I'm debating switching to 3.27's in that as well.

:shrug:

I could not stand the stock gears.. 5th was too steep and it felt like it had ZERO bottom end

4.10's felt great woke the car right up
 
I have 3.90's and get 20 MPG on the freeway cruising at 2500 RPM.

My car became a slug when I installed Saleen 18x10 wheels in the back, so I got that ratio to get back what I had plus a little more. Now, 5th gear is actually useful.
 
:shrug:

I could not stand the stock gears.. 5th was too steep and it felt like it had ZERO bottom end

4.10's felt great woke the car right up

5th has zero bottom, but since I don't shift into it until what, 140mph? I don't mind lol.

I drive my car year round in MN, and I don't need any more torque in first than I already have, but I suppose 4.10's could let me take off in second easier in the winter. But I drive a lot of freeway and don't mind the low revs at 80mph. Someone who never sees highway for hours at a time would feel differently I'm sure.

Just saying that different uses mandate different gears. And gearing advantage falls off as speeds climb. In a 1/4 mile gears can shave off tenths, but from a roll gears are no substitute for power. Every time you shift up, you give up advantage. If that matters to you. Again, usage dictates gearing. I'm thinking 3.73's instead of 4.10's for myself, but I haven't ever heard anyone dog 4.10's, ever. Which says a lot.

At the end of the day, even in the 1/4 mile, we are talking a few tenths. You can make that up with a few power mods if that is important to you. Not for the same money, for sure, which makes gears the cheapest set-of-the-pants mod dollar for dollar hands down. Not counting install :) But on the other hand, gaining a few 1/4 mile tenths in tires makes no difference from a roll, but gaining a few tenths from breathing mods pays off in more accel. up top as well without losing the loping revs on the highway. I'd save gears for after cams or something which moves your powerband north a 1000 rpms or more.

Does that make sense?
 
Curious. Why?



To be honest, i'm not much of a 1/4 mile racer. I rarely make passes at the track, so shaving 0.1 here and there isn't that much of a big deal to me.

I just love the feel of driving with the taller gears on the freeway. To be in 3rd at 45MPH and roll on the throttle past 70 and then shift into 4th feels great to me. I've driven friend's 4.6L's with 4.30's and even 4.56's and just didn't like it. It felt like on the highway i was running out of gear and wheezing. With the 3.27's, I felt as if i could stay in the gear longer when it started pulling hard.

I dunno, i'd rather make the car faster with HP rather than gear multiplication. I HATE how short 1st gear is in my 5.0 and HATE driving on the highway with it with 3.73's :(
 
my 98 cobra has 3:27's in it and I hate them they suck > BAD > I am going to put 3:73's or 4:10's in my car as soon as possible. my 96 gt had 3:55's in it and it was nice and snappy for a bone stock car if all you wanted to do was drive around town and get snoked by every Honda you see > go with something 3:73 3:90 4:10 4:30 any of those gears will make you smile
 
I have 4.10s and regularly pull down 25-26 HWY doing about 80MPH.

I love em! It makes 5th gear feel like 4th. And I use 2nd if I'm starting off downhill or on a flat surface under normal driving.

I would recommend 3.73s as MINIMUM on a 2v 4.6.
 
I'm another with a 4.10 gear sitting in a box in my garage and still running the stock 3.27 gear.

I just don't feel the urge to change. Performance wise I am pretty happy with the car and as mentioned here, it is kind of nice shifting into 4th at 160 KM/H.

All that being said I have actually never driven a 4.6 with 4.10's out back other than my friends 05 S/C 500 rwhp monster which is not what mine would feel like with 4.10's anyway.
 
if you plan on installing cams like you said a lot of them require 3:73's or steeper.

I have 3:73's installed in my car and wish i went with 4:10's. I probably will switch to 4:10's when I go to a 31 spline rear end

I think you will be happy with the 3:90's

I did the same here!!:nonono:
Did 3.73's cause i feared the gear,then a year later went to 4.10's,and now i am thinking 4.30's .My GT has been cammed for the last 3 years now,an i'm really filling that she needs more gear.
Anything lower then 4.10's in a "modular" equipped mustang is a waste of money unless you plan to add a blower/supercharger down the road.
Another thing,can't compare a pushrod motor with an overhead cammed motor,both operate in different rpms when it comes to making hp,and torque.
In an old muscle mustangs issue they had a chart to compare what gear worked for both the 5.0,and 4.6 that would be a good comparisson to each other.....

5.0L= 4.6L

3.55=3.73
3.73=4.10
4.10=4.30
4.30=4.56

One thing is,it's all about fearing the gear with most.:shrug:
 
CHANGE UR GEARS I want too soo bad and i cant wait to get it done. When you do get a tuner too that way the computer from ford that was so "perfect" from the factory as ur friend would say know that you have a diff rear and your speedo is correct
 
GAH STUPID IDIOT, dude 4.10s here and love the hell out of them. i slam em at the track on the weekend and daily drivem on monday thru friday, and still get 23mpg.:) oh my. in my opinion depending if you drive highway or city driven or even if its your daily driver at all. i think its the best couple hundred dollar up grade you can do, but thats my opinion