<P>From the factory mustangs usually come with a 2.73 gear ratio unless you have an svo which in '84 they come out with 3.45 and in '85 and '86 3.73 was standard. Yoe had 2 options for different gearing in mustangs: 3.08 for 5-spd cars and 3.27 for autos. Changing the gears is one of the first things that i would do to a stang. Then we get into choices of different ratios. so here is my opinion on this subject. First you have to decide what you want to do with your mustang. Is it going to be a daily highway driver? A Sunday Driver? Will you be stuck in the city(stop and go traffic)? or just a weekend dragracer? You basically have 6 choices for gears: 2.73, 3.08, 3.27, 3.55, 3.73, and 4.10. the first 3 gear ratios are better for top-end, high speed performance, and the all important fuel economy to the highway commuters. 3.73 and 4.10 are better for acceleration and low end responsiveness. the gear ratio that i have left out was 3.55. it is kind of an all around gear you get fuel economy and still have the power to pass cars at will on the free way.</P>

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Added by MD to clean up another sticky:
Gear calculator website thread:
https://mustangforums.com/m_99648/tm.htm

 

buzz...gears could be an option for the factory as well up to a 3:73 I saw this when I ordered mine in 89

 

ok my sources did not inform me of that. anyhting else top add?

 

yes..they make a 3.90 gears

 

So let me get this strait...my 95GT has 2.73s? No way it's that tall.

 

true unless it is an automatic or was ordered different.

 

how do i figure out what gears i have now. </P>


i have an '89 that came with a 2.3 and 5 speed. but that is about to come out and a 351w and C6 going in.</P>

 

MORE THAN LIKELY YOU HAVE A7.5 REAR END AND I WOULD RECOMEND THAT YOU CHANGE IT OUT FOR AN 8.8 REAR. THE GEARS ARE PROUBALLY 2.73. I WOULD GO BACK WITH SOME 3.55 BECAUSE YOU WULL NOT HAVE ANY OVERDRIVE UNLESS THIS IS JUST GOING TO BE A RACE CAR.

 

3.55 is what i want but still need to know how to identify what i have. would hate to go buy something that i may already have.

 

Theres nothing wrong with that 7.5 rearend as long as you dont go running slicks on it!And being that it was a 2.3 and a 5 speed it most likely has anywhere from 3.08's to 3.55's.My 1989 2.3 with an A4LD had 3.73's from the factory.And i am still currently running the 7.5 and have been for 3 years now behind a 331 with no problems at all.</P>


Now thats not to say everyones is that good.If you can or you happen to run acrossan 8.8for cheap i would get it for sure and atleast keep it until the 7.5 gave out.But running around on the street on regular radials you shouldnt have a problem.</P>


To tell whats in your rear look at the rear axle tag or lift the car and count how many times the drive shaft turns in comparison to the rear wheels.</P><edited><editID>TheGmKiller331</editID><editDate>38023.9970833333</editDate></edited>