Drivetrain 89 LX Sport 5.0 5spd, swap out rear gear

I've got the stock 2.76:1 rear end, would like to change to something quicker, yet keep it streetable. I've read in articles that having a steeper gear has actually improved average gas mileage, as you can run in rpm ranges where the engine is more efficient. How does one know what is the most efficient rpm range for their engine?
 
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All going to vary wildly on your driving style. Biggest difference in fuel economy will come from your right foot.

I have 3.73s and a 5-spd and I get terrible fuel economy simply based on how I drive. I'm lucky if I average 15mpg.
 
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Is your stang a daily driver? If not, don’t worry about it. I’ve never worried about gas mileage in any of the stangs ive owned. I’ve got 3.73’s and I love em.
 
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standard is for 5 spd to go with 3.55's and AOD 3.7'3's for best "all around" driving.
Only get FORD gears and the updgraded install kit.
You will need to swap out the speedo gear to match the rear gears
 
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standard is for 5 spd to go with 3.55's and AOD 3.7'3's for best "all around" driving.
Only get FORD gears and the updgraded install kit.
You will need to swap out the speedo gear to match the rear gears

Similar idea, just different ratios.
I see the standard for a 5 speed as 3.73's and autos 4.10's.
And I agree with the ford racing gears and bearing set.
 
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I'm not a big fan of 3.73s with a stick, but that's because highway cruising here is 80-90MPH and I hate trying to use 5th gear to accelerate to pass

But that's more personal preference. I like a good highway cruiser
 
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I don’t do much highway driving in my car. Driving Around town with my 5 speed and 3.73’s works for me. I would consider 3.55’s though.
 
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I get about 18.5 mpg daily driving, rough number crunching would drop that to 14.8 with 3.55 and 13.9 for 3.73. I'm guessing the fun quotient will out weigh a 30% increase in gas expense. Thanks for the input.
 
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That's why I just refer to it as "Smiles per gallon".

I do have a set of 3.27's I may swap in at some point. Undecided. The 2.73's blow overall, but one of the funnest cars I ever drove was a 3.08 equipped LX with a GT40P engine combo. Enough power for that gear set.
 
I get about 18.5 mpg daily driving, rough number crunching would drop that to 14.8 with 3.55 and 13.9 for 3.73. I'm guessing the fun quotient will out weigh a 30% increase in gas expense. Thanks for the input.

I have 3.55s and my car averages 19-20MPG just driving around. Of course less if I beat on it alot. I don't think you will notice much difference in MPG unless you spend a lot of time running 70+ on the highway.
 
Sorry for my "quote ineptness".

From Mustang5L5
That's why I just refer to it as "Smiles per gallon". I do have a set of 3.27's I may swap in at some point. Undecided. The 2.73's blow overall, but one of the funnest cars I ever drove was a 3.08 equipped LX with a GT40P engine combo. Enough power for that gear set.

My stock '83 with the 3.08 and T5 got as much as 27MPG on a road from Amarillo to Ft. Worth when the speed limit was 55MPH. You didn't chance 60MPH through the tiny, one cop towns. I rarely looked at city but am pretty sure it got around 16MPG or so with my driving habits. Fast forward with the same drive train and a good 100HP more engine and my MPG is definitely less than 12MPG but I rarely hit 5th gear because the north Dallas freeways are suicide to drive on.

So, it is "Smiles per gallon" for me!