• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

To anyone who has 3.73s

  • Thread starter Thread starter Opal50
  • Start date Start date Jul 13, 2007
  • 1
  • 2
Next
1 of 2 Next Last
O

Opal50

New Member
May 16, 2007
21
0
0
Jul 13, 2007
#1
  • Jul 13, 2007
  • #1
I going to install a new ring and pinion next week and I am still debating between 3.73s and 3.55s. I'm not really worried about the high rpms, but I'm wondering if the 3.73's make first gear useless. Can anyone comment on this? BTW, I believe I'm running a 245 40 18 which would give me a 25.72" diameter.

Thanks
 

maxine-70

20+ Year Stangneter
Mar 27, 2003
273
1
18
louisville, ky
Jul 13, 2007
#2
  • Jul 13, 2007
  • #2
there isnt a tremendous amount of difference between 3.73 and 3.55 gears. what gears are you taking out? what transmission are you using? transmission first gear ratios will play a significant role. an automatic typically doesnt have the steep first gear ratio a manual has....and manuals usually come in at least two different gear ratios, some having about 3:1 first gears, some 3.27, like the TKO i put in. the numerically lower your first gear ratio is the more you will benefit from numerically higher rear gear ratios and vice versa. im putting the 8.8 back in my 86 today; it was out for a 3.90 gear install and a posi rebuild. the 3.90 rear gear with 3.27 first gear will make first gear extremely snappy and wind out quickly. i dont mind that though as i wont be racing it, its just a fun street convertible
 

bullitstang1313

Member
Jan 21, 2003
713
0
16
Indianapolis / Columbus, Indiana
Jul 13, 2007
#3
  • Jul 13, 2007
  • #3
I have the a T-5Z with a 2.95 first gear ratio so that plays a big difference, but I love my 3.73's. I don't have any issues with first gear, seems to be plenty long enough.
 

ninety15.0

New Member
Mar 10, 2004
1,336
0
0
Jul 13, 2007
#4
  • Jul 13, 2007
  • #4
I'm running 3.73's and i hate to say it but i wish i went with 3.55's. There are times i love the 3.73's but first gear is tough to hook in (nothing past 1/2 throttle will hold) and second also spins quite willingly. I wish my highway rpm were a little lower. My next tranny will be a t-5Z with the longer 1st and 5th gears to make the rpms more manageable.
 
O

Opal50

New Member
May 16, 2007
21
0
0
Jul 13, 2007
#5
  • Jul 13, 2007
  • #5
Yeah I forgot to say I have the stock 5 spd manual in a 94 gt. BTW, I should have 2.73s in there now right? I've heard things about 3.08s so I'm not sure. Also do you know the first gear ratio in a stock 94 gt?
 

conartist

Member
Dec 4, 2002
77
0
6
Windsor, Ontario, Canada
Jul 13, 2007
#6
  • Jul 13, 2007
  • #6
I would ask yourself what kind of driving you will be doing? If you are driving in city streets with lots of lights and such, the higher gears, you will be shifting a lot. Not that that is bad, just a pita sometimes.

I have 3.73s and love em.
 

jimdrechsler

Member
Jun 29, 2006
248
1
18
Jul 13, 2007
#7
  • Jul 13, 2007
  • #7
i have had 3.73's and 3.55's. 3.7.3' were in my old convertable and 3.55's are what i have now. i think it is one of those things where you will be happy with either. you will question whether or not you should have gone with the other gear regardless of which you choose. I do that now. I do like the 3.55's on the highway, especially when racing someone. can go to third for a while when downshifting. first gear with 3.73 is very quick, but i liked that when i had that. i dont miss it now though as i am happy with the 3.55's
SO, what i am saying is that you will be happy with either one i think. i am 51% for 3.55's and 49% for 3.73's!
dont know if this helps or not
 

squeak93

15 Year Member
Jun 2, 2005
2,276
367
164
Joplin, Missouri
Jul 13, 2007
#8
  • Jul 13, 2007
  • #8
Had 3.73's in my first 5.0. Small bolt ons with a stock t5. Great gear for that car.


My old 04 gt with a 5 speed had 4.30's and it loved them. If you get tired of shifting too much in traffic, just take off in second!
 

rj95svt

Member
Jan 11, 2007
422
0
16
Hayden, AL
Jul 13, 2007
#9
  • Jul 13, 2007
  • #9
I am having 3.73's put in my 95 cobra as we speak. I think that with the extra weight of the 94 95's the 3.73 will be the better gear. The first gear in the stock T5 is 3.35. I'm hoping to pick my car up this afternoon. If I do I'll reply about what I think about them tommorow.
 

daviszx3

Member
Jun 3, 2007
42
0
6
maryland
Jul 13, 2007
#10
  • Jul 13, 2007
  • #10
i had 373's in my 89 conv. and loved them but it was a aod
 
R

red95gtconvert

New Member
May 29, 2006
382
0
0
Ponca city, OK
Jul 13, 2007
#11
  • Jul 13, 2007
  • #11
I installed 3.73's in my 95 GT vert and think they are a great gear ratio, they were pretty easy to install other than compressing the crush sleeve while laying on my back in the driveway.
 
V

v8only

Active Member
Jul 3, 2003
2,378
22
49
Jul 14, 2007
#12
  • Jul 14, 2007
  • #12
really the debate is between 3.73's and 4.10's, NOT 3.73s, and NOT between 3.73's and 3.55's, UNLESS you do ALL highway drivetrain, or run a power adder.

other than that, I run 3.73's with a t5 with a 3.30 first gear, and have plenty of first gear. First gear pulls like nothing else. My buddy ran 4.10's and a 3.30 first gear, and had no issues either.

Anyone having traction issues has a few things to look at.

1. dial in your suspension. Are you running rear lower and upper aftermarket control arms??

2. how is your weight transfer? Make sure the rear end is VERY stiff, and that will go a long way, even if you don't soften up the front end.

given that, I've got a gt40p motor, and all those mods, and first gear still spins intself to redline. However, i've found that a lot of practice launches helps tremendously.

Not only that, just run a street drag radial full time. that's what I plan on doing. My buddy is putting down over 300 to the wheels, with 4.10 gears, and runs a drag radial on the street, and can't even chirp the tires!
 

rj95svt

Member
Jan 11, 2007
422
0
16
Hayden, AL
Jul 17, 2007
#13
  • Jul 17, 2007
  • #13
I got my car back yesterday after my gear swap. That was the best money I've spent so far!!!!!! First gear is in no way to short after putting the 3.73's in. Make sure you buy Ford racing gears. This is the first set of aftermarket gears I've bought and it's the last set. These gears make a slightly audible whine and I've never had that issue with the ford gears not to mention it cost me more to get them set up. The owner of the shop I used said that most time ford gears can be set up using the factory shims but the aftermarket gears are ussually no where close which makes them take longer to install.
 

maxine-70

20+ Year Stangneter
Mar 27, 2003
273
1
18
louisville, ky
Jul 17, 2007
#14
  • Jul 17, 2007
  • #14
if your gears have a slight whine, its because they werent set up 100% correct, not because they werent ford motorsport gears. they all set up the same. just because you took out an oem set and put an FRPP set in doesnt necessarily make it a drop in, they all have to have the shims checked. there are several companies that make ring and pinion gears. i went with motive gear, as they are the only company making the 3.90 8.8 gear that i wanted. no issues with them. who made the gearset you bought?

i thought 3.90 would make the shifting go quite fast but it really didnt. i couldve gone with 4.10's. it sure does pull hard though!
 

Black Sun 5.0

Founding Member
Mar 23, 2002
1,337
0
36
L.I., N.Y.
Jul 17, 2007
#15
  • Jul 17, 2007
  • #15
OK, factor this in: a Vortech supercharger. What gear would you go with then?
 

rj95svt

Member
Jan 11, 2007
422
0
16
Hayden, AL
Jul 17, 2007
#16
  • Jul 17, 2007
  • #16
The guy that set my gears up spent a day and a half on them. He said no matter what he did he sould not get them as good as he liked. The gears I got I traded for and they was new in the box but weren't a common name brand. My point about the ford gears is that most of the time (not all) they can be set up using the factory shims which makes the install go much faster.
 

Fishhawk

New Member
Jun 10, 2004
281
0
0
Michigan City, Indiana
Jul 17, 2007
#17
  • Jul 17, 2007
  • #17
At first I wished I had gone with 3:73's, but now with the gas prices the way they are I'm glad i went with 3:55's. The car cruises at 2500 RPM's at 75 MPH. Nice and comfortable.
 

85_SS_302_Coupe

it sucks (I know) to be on the receiving end
15 Year Member
Nov 11, 2003
6,945
1,598
223
Northern KY
Jul 17, 2007
#18
  • Jul 17, 2007
  • #18
You're talking about 2-300rpm difference at highway speeds.....go with the 3.73s. If you have traction issues it's not the gear's fault....get better tires, get control arms, dial in the suspension and then most importantly tighten up the loose nut behind the steering wheel
 
B

Boss 351

Here sthhhhhhhheeeve take a picthh of my man flowe
Jul 13, 2003
2,433
23
48
Canada
Jul 17, 2007
#19
  • Jul 17, 2007
  • #19
You want me to play with my nuts? I like the 3:55's
 

MadDAWG

New Member
Aug 19, 2002
25
0
0
Michigan
Jul 18, 2007
#20
  • Jul 18, 2007
  • #20
You better find out what gear you have now. If you have 3.08s and goto 3.55 you are going to waste your money. You won't even notice the change. I went from 3.27s to 3.73s and it was a big waste of time and money. My current car has 3.73s and a 4cly T5 when I bought it. That was a little step in first gear. (3.95 x 3.73 = 14.73 o.a.r.) I swaped in a t5z (11.00 o.a.r.) and now I want to swap rear gears.

So another way of putting it is 3.73s all the way!
 
  • 1
  • 2
Next
1 of 2 Next Last
You must log in or register to reply here.

Similar threads

3
Eight inches is enough for me...
  • 351MooseStang
  • Nov 27, 2025
  • 1974 - 1978 Mustang II Talk & Tech
Replies
5
Views
575
1974 - 1978 Mustang II Talk & Tech Mar 2, 2026
Bullitt347
Place to Avoid: Jamison Auto Group in Gulfport, MS
  • D Durden
  • Oct 20, 2025
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • 2 3
Replies
46
Views
3K
1965 - 1973 Classic Mustangs -General/Talk- Jul 16, 2026
Noobz347
Progress Thread "Alter Ego" White 1993 LX 5.0 5spd
  • idareu
  • Sep 9, 2024
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2 3
Replies
42
Views
3K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Feb 19, 2025
idareu
Which one of these 3 intakes make the most sense for my 331 combo
  • from6to8
  • Jul 25, 2024
  • 1994 - 1995 Specific Tech
Replies
7
Views
2K
1994 - 1995 Specific Tech Jul 26, 2024
AeroCoupe
98 GT PI Swapped Engine Fires, Dies Immediately NOT PATS
  • MMccPerformance
  • Dec 2, 2023
  • SN95 4.6L Mustang Tech
Replies
3
Views
2K
SN95 4.6L Mustang Tech Dec 20, 2023
Yel2002GTAuto
Y
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?