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Where to get a complete diff, want iron witb 3.73 or higher.

andrewtac

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I was going to do a gforce 9", just not sure I need it. I do want an iron housing and 3.73 gears (maybe higher). I've seen the complete 3.55 iron. Anyone know where I can get one built to order?
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Angrey

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In Super 8.8, the only pumpkins I've seen new are 3.73 and 3.55.

Ford Racing offers the 4.09 ring/pinion set (for the Super 8.8) and that's as high as they can legally go. Though you'd be hard pressed to find one for sale as only a few of us out there have paid to convert it.

You can get the higher ratios (4.30, 4.56, etc) from US Gear, Yukon, Motiv, etc but you'll have to pay a small fortune to have it swapped out by a shop (that has the tools and experience to swap the Super 8.8). I paid $800 for the installation 4 years ago and that was at the bottom of the market then. Most shops have never done the swap and it's considerably more involved than a traditional 8.8 solid axle swap out.
 
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andrewtac

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In Super 8.8, the only pumpkins I've seen new are 3.73 and 3.55.

Ford Racing offers the 4.09 ring/pinion set (for the Super 8.8) and that's as high as they can legally go. Though you'd be hard pressed to find one for sale as only a few of us out there have paid to convert it.

You can get the higher ratios (4.30, 4.56, etc) from US Gear, Yukon, Motiv, etc but you'll have to pay a small fortune to have it swapped out by a shop (that has the tools and experience to swap the Super 8.8). I paid $800 for the installation 4 years ago and that was at the bottom of the market then. Most shops have never done the swap and it's considerably more involved than a traditional 8.8 solid axle swap out.
Where'd you see the 373?
 

Angrey

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Dave2013M3

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I just did a 4.09 conversion from my 3.73's, it changed the car. I wish I did this earlier. If you have a manual MT82D4 t he gearing was completely neutered. The 4.09 brings a lot of that back. I would just get a 3.73 new diffy and have the 4.09's done before install. The hardest part of the install is pulling that whole IRS subframe out.
 

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andrewtac

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I am leaning back towards the gforce. It is so much easier to get 9" gears. I could even get a spare pumpkin for it.
 

K4fxd

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Ford Racing offers the 4.09 ring/pinion set (for the Super 8.8) and that's as high as they can legally go.
Do you have a link or a reason it is illegal?
 

Angrey

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Do you have a link or a reason it is illegal?
When I spoke with US Gear, they have a contract with FRPP to make their 4.09 ring/pinion set which is exclusively licensed for FRPP (meaning US Gear can't offer it of their own, at least that particular product). He indicated that when they were doing the deal with FRPP, 4.09 was the highest ratio they could go and still stay within some sort of CARB or certification (for economy).

4.09 isn't illegal, it's just for FRPP to maintain whatever restrictions that's the highest gear ratio THEY can sell. Which explains why they don't offer the 4.30 or 4.56.

You can still get all of those ring/pinion sets, you just can't get them through FRPP. So maybe "illegal" wasn't the right term.
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