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3.31 vs 3.55 Gears

pro 5.0

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Those that upgraded their gears, do you guys get a loaded dif or just buy the gear and have a shop swap them?

Also, going from a roll, how much difference does the 3.55 make vs 3.31?
If you have a PP car you can get a loaded diff from Ford but it will have a normal trac lok with the clutches and not the torsen. Cheaper to buy just the gears but more convenient to swap out the whole assembly.
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whatsup62

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If down time matters its much faster to do the loaded center section.
Going from a roll you are now taking away the advantage of the lowwr gearing (3.55"s).
 

pro 5.0

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What about non-PP? Can those be upgraded?
Direct fit for non PP cars meaning same clutch pack differential as OEM.
 

sonicc

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I was adjusting my sway bar this evening and decided to take a look at the differential while under there. I noticed on the sticker it says "8.8 3l55"

Does that mean it has 3.55 gear?
 

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pro 5.0

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I was adjusting my sway bar this evening and decided to take a look at the differential while under there. I noticed on the sticker it says "8.8 3l55"

Does that mean it has 3.55 gear?
Yes it means 3.55 ratio and limited slip
 

SVT-DADDY

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3.55 loaded diffs can be had for $900. Swapping the diff I can handle. Setting up gears, not so much.

Makes the loaded diff a much better value for me.
 

TooSoonJunior

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I have never been able to find a 3.31 loaded diff. Have found them, but once ordered I always get a cancellation notice saying the part is not in stock and indefinite timing to be back in stock.
 

whatsup62

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Have a loaded 3.73 for sale and 3.31's with carrier for sale.
 

scottmoyer

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For anyone looking at mileage differences between 3.31 and 3.55s, there doesn't appear to be much at all. I filled up my 2017 GT with 3.55 gears on my way to work, a 150 mile roundtrip drive, and I got 24.8mpg at 75mph. The next day, I drove my 2014 GT with 3.31 gears, filled it up on the way to work and got 24.9mpg at the same 75mph. Now, the 2017 only has 1500 miles on it, so it's not even broken in yet!!! The 2014 has 33k miles.
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