View Full Version : Is their a gear set between 3:73 & 4:10 ??

Dave B.
10-15-2005, 01:30 AM
My car came with 3:55's then I went to 4:10's,
now I have 3:73,,,,does any company make something between the 3:73"s and 4:10's ?? like a 3:90 or 3:85 or 3:95 ??? anything inbetween at all??

I loved the 4:10's however I think if I went back to the 4:10's it would cause more drive line damage, a guy from Ford said the 03-04's IRS is not strong enough to take long time abuse from an engine pumping out a lot of HP and 4:10's in it,

He said something about the 4:10's causing too much torque to the drive line and in addition,, that I was lucky to have only wrecked a drive shaft,,

most wreck their IRS and more I guess, is there anyone out there thats been cranking on it with 4:10's for a long long time, without ever having any drive line problems from it at all??

10-15-2005, 07:43 AM
I'v seen a set of 3.90's that are new just for the reason for being in between 3.73 and 4.10. I believe I'v seen them in either my 5.0 or MM & fast fords mag.

10-15-2005, 08:13 AM
try this web site for RPM calculation for differant gear ratio's www.woodyg.com/fairlane/info/rpm.html (http://www.woodyg.com/fairlane/info/rpm.html) :thumbsup: just hit on blue box were it say's 61- 73 fairlane's then on the next page go to the bottom of the page and you will see CALCULATION .

10-15-2005, 09:01 AM
the IRS is definitely a weak link, but if you're not planning on going over 650rwhp, then get the DSS level 2 halfshafts and you'll be set...I just got the level 5's (900+rwhp) and they should hold up fine...:thumbsup:

10-16-2005, 05:24 AM
My car came with 3:55's then I went to 4:10's,
now I have 3:73,,,,does any company make something between the 3:73"s and 4:10's ?? like a 3:90 or 3:85 or 3:95 ??? anything inbetween at all?? ~:edmond:Seems I can't paste a link - so you'll have to Google it "Pro 5.0" +"3.90" will get the info you seek. 3.90s are available. :cool:

10-16-2005, 07:33 PM
Why can't you post a link Kilroy?

Dave B.

To me this whole scenario is wasteful but then that's just my opinion. Your car came with 355's and you put in 373's which you felt were not enough but 410's would be too much. If you have 373's and you already spent the money to have them installed, why would you go and spend more $$ to have a set of 390's put in? Do you think you are really going to see that much of a difference with a lower .17 gear ratio? I doubt you'd be able to tell the difference. Of course, this is just my unprofessional opinion.. :retard: :crazy:

Dave B.
10-16-2005, 07:39 PM
because I can afford too!!! :banana: :moon: :banana:

10-16-2005, 07:59 PM
because I can afford too!!! :banana: :moon: :banana:
I appreciate it! You do some good R&D :rotf:

Dave B.
10-16-2005, 08:10 PM
yea I know,,,,,I had to do that,,,even though I want to some times I dont insult people personaly on this board, when others do,, It just goes to show how old some are,

heres thing with these gears man,,,,,,when I went to the 4:10's it was phenominal,,,,,but im convenced now the 4:10's had a lot to do with the damage it caused to my OEM drive shaft, thats why I went to 3:37's then of course I found the fix which is the carbon drive shaft,
but what this other guy does not know,, that I do know,,

Is that 3:73's are not anywhere close to 4:10's
there not even in the state,,,,,3:73's feel more like 3:55's,,,in fact if I did not see 3:73 on the box they came in, I would have swore they were 3:55's

the other thing is, Im running 18 inch wheels that lower even further

Dave B.
10-16-2005, 09:05 PM
it was suggested that 5.0 mustang 3:90 rear end gears would work, but will they fit? will they work ??

I was warned not to use anything but Ford or Motorcraft gears and they only do the 3:55, 3:73, 4:10's and so forth,

I guess in his defence it would be a little silly to go thru all the trouble to try and get between 3:73's and 4:10's I just wish I would have found out that this Carbon shaft was going to fix my problem before I took out the 4:10's

I shall miss them indeed. :bawling:

10-16-2005, 09:20 PM
It was not an insult, it was a question as to why you would do that when the difference would be miniscule?? You won't feel a big difference with 390's over 373's.

I'd hate to see you be dissapponted with such a small gear change? However, as you pointed out, you can afford to change them so go for it.

Dave B.
10-16-2005, 09:35 PM
but see theres a HUGE, GIANT differance between the 4:10's and 3:73's
I was just in a set of 4:10's about a week ago, I left the car at the shop and when I picked it up with the 3:73's in it my first reaction was to go home and sharpen the Hari Cari knife, it was that bad, all the huge torque I used to enjoy greatly was no longer,

so there is a giant differance, but I think I will leave it the way it is now, after driving around for a week I'v gotten used to it, kind of like going from a V-twin super bike to an in line four Super bike, the power is just in a differant place now, and I never really liked the 4:10's on the interstate anyway, they just felt wrong, but for around town you cant beat 4:10's and a grin :D

10-17-2005, 10:16 AM
Why can't you post a link Kilroy?Paste, not post... The link I wanted to paste into my thread was pretty involved & it would be easier for Dave to Google it himself.
*I'm sure there's a perfectly good reason for disallowing the ability to cut/paste into a post and I hate to fat finger stuff when it comes to URLs...

On gears, I agree that you can't really feel a single step all too much it usually takes two. The 3.90s I spoke of have been out a while now & I've read where others have used them. Should I ever go with a solid axle I'll definately put a set in. I was gonna do it last year when my diff started leaking until the Service Manager told me Ford replaces the whole pumpkin under the TSB & I would have to fund the swap after they'd swapped out the center section. It's alot more expensive doing work on an IRS setup than live axle.

10-17-2005, 11:52 PM
Richard......paratrooper82d has the 3.90's in his car and he's had absolutely no issues with them...........fun as hell to ride in too :D

10-18-2005, 06:41 AM
I have got the Motive Racing 3.90 gears in mine. Pulls really well through the gears, and also is pretty good on highway driving. I would recommend them.

Dave B.
10-18-2005, 11:01 PM
this is great news, 3:90's are where im going,

I liked the 4:10's but they may have been too much, you know another thing any of you who were thinking of buying a Wideband gauge and putting gears in, best first listen to this factoid!

you cannot read wideband without hooking it up to a printer or laptop or some method that allows the gauge system to print out a record because I had 4:10's in when I bought my wideband and i thought the gauge was broken, the engine revs way way way too fast with 4:10's in to read the gauge, the think just spewed numbers everywhere so fast that it was a usless waist of money,

The moto??? if your planning on getting gears and a wideband, best get the wideband first, because it would work even better than it does now if I had 3:55's so tune first then get gears or trust me,,,,you will regret it.