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Wanting to upgraded my 3.15 gears "please help"

DarkVader0911

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So I have 3.15 gears in my 15 v6 manual and I know I can't just swap out to 3.55 or 3.73 gears without changing the rear diff, my question is if I go to AmericanMuscle and buy the loaded differential will my current axles work, it says it requires 34 spline axles and I'm not sure what spline my current axles are. When I go to ford parts and look up axles it seems that all models of the mustang use the same axles, well at least the part number is the same. Does anyone have any idea if just buying the loaded diff will work.

This is what differential I'm talking about
http://www.americanmuscle.com/frpp-irs-355-loaded-torsen-diff-1516.html

And what would be some good supporting mods to go with upgrading the IRS

Thanks in advance guys and sorry if this has been asked before
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EXP Jawa

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All of the S550 axles have 34 tooth spline shafts, so you're good there. The axle carrier that you've linked to is a very clean way to do the swap, and minimizes the labor needed, but it is more expensive than just and ring & pinion set and suitable differential. All you really need is:

http://www.americanmuscle.com/frpp-34spline-88-irs-diff-2015gt.html
and
http://www.americanmuscle.com/frpp-355-gears-2015.html
Plus, of course, the bearings/tools/supplies needed to do the install. But if you've never set up ring and pinion gearing before, swapping the whole axle assembly makes it much easier...
 

EcoSwag1990

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You'll also need the Whipple flair tool
 
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DarkVader0911

DarkVader0911

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Thanks so much so those two parts is all I need for a shop to install them? I currently don't have a place to do it my self so I'm going to have A local mustang shop do the work. I haven't decide between 3.55 or 3.73 gears for my nitrous setup,

While the shop is down there replacing the gears what else would be a good addition to the IRS and driveline system
 

69mach1-395

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Maybe 3.15 is best for nitrous already...
 

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DarkVader0911

DarkVader0911

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And I'm not always using nitrous so when I'm not using it I would like a quicker gear
 

v8440

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More gear isn't always quicker. There are cases where available torque is so high relative to vehicle weight that less gear helps calm the car down at launch and causes it to not hit the tires so hard. That said, I'm not saying 3.15's are your best choice for nitrous, just that it's not impossible.
 

2015 Silver GT

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More gear isn't always quicker. There are cases where available torque is so high relative to vehicle weight that less gear helps calm the car down at launch and causes it to not hit the tires so hard.
Well said.
 
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DarkVader0911

DarkVader0911

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Appreciate the help, didn't mean to come off as rude or anything, right now using track apps I did a 0-60 launch on a 50 shot and ran 5.4s, granted I drive a manual and not the best at launching the car, is that a pretty good number I want to get to 4s at least, now I am going to increase the shot to 100 and will be going to the local tuner to get tuned. Currently on an unleashed 93 tune witch wasn't setup for the nitrous,
 

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v8440

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What sort of nitrous setup do you have? Meaning wet or dry, injected where?
 
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DarkVader0911

DarkVader0911

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NX Wet System 3.7 throttle body plate system,
 

gsxr1300

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Thanks so much so those two parts is all I need for a shop to install them? I currently don't have a place to do it my self so I'm going to have A local mustang shop do the work. I haven't decide between 3.55 or 3.73 gears for my nitrous setup,

While the shop is down there replacing the gears what else would be a good addition to the IRS and driveline system
Check on the labor prices, It may end up cheaper to just buy the part in the link you originally posted and it will be done right. I have seen a few people post that they had problems after shops not doing the gear swap correctly.
 

mrblanche

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More gear isn't always quicker. There are cases where available torque is so high relative to vehicle weight that less gear helps calm the car down at launch and causes it to not hit the tires so hard. That said, I'm not saying 3.15's are your best choice for nitrous, just that it's not impossible.
This is some of the theory behind the use of old Powerglides in drag cars.
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