3.55 vs. 3.73 Gears

9

95Doug5.0

New Member

Nov 18, 2004

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Nov 18, 2004

#1

• Nov 18, 2004

• #1

What should I get, 3.55 or 3.73 gears? Primary concerns with the 3.73's are gas mileage and what kind of RPM's will I be pulling at 75mph if I have 17 inch rims? I already know how quick the 3.73's get up there, my buddy has them, but I was curious if this is going to be a toll on my engine and if it is going to effect my gas mileage SIGNIFICANTLY.

 

pleasehelp

New Member

Mar 11, 2003

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Poplar Grove, Il

Nov 18, 2004

#2

• Nov 18, 2004

• #2

Go with 3.73s. There is not that much difference in them. There are some people driving around with 4.10 in 5 speed, but I wouldn't recommend that.

Welcome to the boards BTW!!!

 

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9

95Doug5.0

New Member

Nov 18, 2004

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Nov 18, 2004

#3

• Nov 18, 2004

• #3

thanks for the #'s and thanks for the welcome. I'll try to get some pics of my black beauty up ASAP! Heading down to the track on Friday to see what I can do

 

Joes95GT

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Jan 23, 2003

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Nov 18, 2004

#4

• Nov 18, 2004

• #4

Those graphs show RPM versus speed which is a little deceptive. The difference in RPM at a 75 is about 200 RPM if memory serves me correctly.

I can't comment about gas mileage. My gears were installed around last October and I haven't put 500 miles on my car since then.

Joe

 

Venom351R

Founding Member

Apr 27, 2002

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MAINE

Nov 18, 2004

#5

• Nov 18, 2004

• #5

Welcome but just that this topic has been so beat to death that theres nothing left to beat.

 

Reactions: Brucebruce

chefster

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May 24, 2004

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michigan

Nov 18, 2004

#6

• Nov 18, 2004

• #6

in same dilema,you can see the difference at 3000 rpms...114 vs 94.big difference if its a daily driver...iam going with the 355..like the new gts are doing

 

Joes95GT

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Jan 23, 2003

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#7

• Nov 18, 2004

• #7

chefster said:

in same dilema,you can see the difference at 3000 rpms...114 vs 94.big difference if its a daily driver...

Click to expand...

You shouldn't compare the stock versus 3.73. There is no basis for comparison. Compare the speed @ 3000 RPM in 5th gear between the 3.55 and 3.73. It's a 5 MPH difference. Unless your car traps 135+ or you like to drive 120 MPH all the time, I don't see the reason for not getting a 3.73.

chefster said:

i am going with the 355..like the new gts are doing

Click to expand...

The new GT needs another another full turn, too. People complain of them being gutless because they don't have enough gear.

Joe

 

Reactions: Brucebruce

stangboy

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Aug 31, 1999

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Nov 18, 2004

#8

• Nov 18, 2004

• #8

3.55s aren't enough gear for our heavy ass cars unless you have a power-adder. I love my 3.73s. They won't make a significant difference in gas mileage.

 

FastGT94

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Nov 20, 2003

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NW Burbs, IL

Nov 18, 2004

#9

• Nov 18, 2004

• #9

I'd go 4.10's I wish I had with my 3.73's. My gas mileage went UP by 1-2 mpg on both highway and in town. I was getting 14-15 mpg in town and after the 3.73's I was getting 16-17 on a regular basis. Yes my car was daily driven at that time.

 

ProKiller

Founding Member

Apr 26, 2002

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PA

Nov 18, 2004

#10

• Nov 18, 2004

• #10

3.73s all the way. not worth the time and money to put in 3.55s unless you plan on putting on a supercharger in the near future and drive about 50 miles a day.

 

9

95Doug5.0

New Member

Nov 18, 2004

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Nov 18, 2004

#11

• Nov 18, 2004

• #11

Well thank you on the advice, I think I am going to start looking around for some 3.73's. Any clues on what brand or anything specific I should know about them before?

 

FastGT94

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Nov 20, 2003

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NW Burbs, IL

Nov 18, 2004

#12

• Nov 18, 2004

• #12

FMS gears or Richmond. I have no complaints about my FMS.

 

F

fiveo'cobra

New Member

Oct 7, 2004

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SC

Nov 18, 2004

#13

• Nov 18, 2004

• #13

FMS deffinatley. They have the tendacy to whine less than others. I would go to gefracing.com for gears. I got my 4:10's from there BRAND new for $139.95 plus shipping.

 

chefster

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May 24, 2004

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michigan

Nov 18, 2004

#14

• Nov 18, 2004

• #14

supercharger and 8o miles aday,,,,,so I should get 355s

 

chefster

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May 24, 2004

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michigan

Nov 18, 2004

#15

• Nov 18, 2004

• #15

supercharger and 8o miles aday,,,,,so I should get 355s?

 

gcomfx.com

Founding Member

Oct 22, 2002

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Nov 18, 2004

#16

• Nov 18, 2004

• #16

Supercharger and 80miles a day....

Yes....

 

D

Darkhorse845

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Nov 17, 2004

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Las Vegas,Nevada

Nov 18, 2004

#17

• Nov 18, 2004

• #17

Welcome to Stangnet! 3.55's

 

final5-0

Mustang Master

Apr 6, 2003

6,817

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DFW Texas

Nov 18, 2004

#18

• Nov 18, 2004

• #18

The difference in rpm's at highway speed between them is less than 150 rpm if I remember correctly. I use 373's and some times I wish I went with 410's.

You can use this to separate opinions from facts.
http://www.allfordmustangs.com/Detailed/608.shtml

Later
Grady

 

chefster

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May 24, 2004

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michigan

Nov 19, 2004

#19

• Nov 19, 2004

• #19

i had 410 when i bought my car ..it was like no first gear and the rpms were to high at 90

 

Joes95GT

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Jan 23, 2003

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Nov 20, 2004

#20

• Nov 20, 2004

• #20

First gear is useless in a Mustang unless you have 2.73 gears. They simply make too much torque, and combine that with a 3.35 first gear and you've got a whole bunch of tire smoke. I can make any car have "no first gear" if I tried hard enough.

My Dad let me drive his old 68 Fastback to Prom when I was in highschool. With a worked HiPo 289, a top loader 4-speed, and a 4.56 gear, that car wouldn't get traction unless you were going 25 MPH in 4th gear.

Joe