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Authorized Brand Dealer
Fulfillment From Multiple U.S. Warehouses
Enthusiast Owned & Supported
Easy Financing Available!
Authorized Brand Dealer
Fulfillment From Multiple U.S. Warehouses
Enthusiast Owned & Supported
Easy Financing Available!
Authorized Brand Dealer
Fulfillment From Multiple U.S. Warehouses
Enthusiast Owned & Supported
Easy Financing Available!
Authorized Brand Dealer
Fulfillment From Multiple U.S. Warehouses
Enthusiast Owned & Supported
Easy Financing Available!
Authorized Brand Dealer
Fulfillment From Multiple U.S. Warehouses
Enthusiast Owned & Supported
Easy Financing Available!
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Ford Racing
Ford Performance Super 8.8in IRS Loaded Differential Housing with 3.55 Gears for Select Ford Mustang 2015-2025
$1,415.00
This product will be available for sale in 2 weeks, but you can pre-order now to receive 10% discount!
Fits 2015-2025 Ford Mustang models, including EcoBoost, GT, V6, Shelby GT350/GT500, Mach 1, and Dark Horse.
This Ford Performance Super 8.8-inch IRS Loaded Differential Housing (M-4001-88355B) is a complete solution for upgrading or replacing the rear drive unit in your S550 or S650 Mustang. Built with a high-strength iron housing and a lightweight aluminum cover, this assembly arrives fully built and ready for installation. It comes pre-loaded with a Traction-Lok limited-slip differential and a 3.55:1 ratio gear set, providing a balance of acceleration and highway cruising efficiency.
The unit features a pinion flange with a 93mm bolt circle and an installed 110mm driveshaft pilot, ensuring compatibility with factory-style driveline components. Please note that custom calibration is required for proper speedometer and shift point correction after installation.
- Manufacturer Part Number: M-4001-88355B
- Differential Type: Traction-Lok (M-4204-M)
- Gear Ratio: 3.55:1 (M-4209-88355A Gear Set)
- Housing Material: Cast Iron with Aluminum Cover
- Pinion Flange: 93mm Bolt Circle
- Driveshaft Pilot: 110mm
- Fitment: Independent Rear Suspension (IRS) equipped Mustangs
🔧 Fitment & Compatibility
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2019-2020 | Ford | Mustang | Bullitt |
| 2024-2025 | Ford | Mustang | Dark Horse |
| 2024-2025 | Ford | Mustang | Dark Horse Premium |
| 2015-2025 | Ford | Mustang | EcoBoost |
| 2015-2025 | Ford | Mustang | EcoBoost Premium |
| 2015-2025 | Ford | Mustang | GT |
| 2015 | Ford | Mustang | GT 50 Years Limited Edition |
| 2015-2025 | Ford | Mustang | GT Premium |
| 2021-2023 | Ford | Mustang | Mach 1 |
| 2016-2020 | Ford | Mustang | Shelby GT350 |
| 2016-2020 | Ford | Mustang | Shelby GT350R |
| 2020-2022 | Ford | Mustang | Shelby GT500 |
| 2015-2017 | Ford | Mustang | V6 |
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Atlus
1340 Cobb Dr, Unit 1, Eustis, FL 32736
352-234-4458
Mon – Fri: 8:30 am – 4:30 pm
Sat: 9:00 am – 2:00 pm
Sun: Closed
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The Atlus Price Guarantee
If you can find the part for a lower price from an authorized dealer/shop, we'll match the price! Reach out to Hello@AtlusAuto.com, our live chat located at the bottom right of your screen, or request an Atlas Price Guarantee, or visit our dedicated APG page to submit a request.
Ford Performance Super 8.8in IRS Loaded Differential Housing with 3.55 Gears for Select Ford Mustang 2015-2025
$1,415.00
This product will be available soon, but you can pre-order now to get on the list before others!
US Based Support - In Florida
30 Days Satisfaction Guarantee
Price Match
If you can find the part for a lower price from an authorized dealer/shop, we'll match the price! Reach out to Hello@AtlusAuto.com, our live chat located at the bottom of your screen, or request an Atlas Price Guarantee, or visit our dedicated APG page to submit a request.
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$1,415.00
$1,415.00
$1,415.00
Fits 2015-2025 Ford Mustang models, including EcoBoost, GT, V6, Shelby GT350/GT500, Mach 1, and Dark Horse.
This Ford Performance Super 8.8-inch IRS Loaded Differential Housing (M-4001-88355B) is a complete solution for upgrading or replacing the rear drive unit in your S550 or S650 Mustang. Built with a high-strength iron housing and a lightweight aluminum cover, this assembly arrives fully built and ready for installation. It comes pre-loaded with a Traction-Lok limited-slip differential and a 3.55:1 ratio gear set, providing a balance of acceleration and highway cruising efficiency.
The unit features a pinion flange with a 93mm bolt circle and an installed 110mm driveshaft pilot, ensuring compatibility with factory-style driveline components. Please note that custom calibration is required for proper speedometer and shift point correction after installation.
- Manufacturer Part Number: M-4001-88355B
- Differential Type: Traction-Lok (M-4204-M)
- Gear Ratio: 3.55:1 (M-4209-88355A Gear Set)
- Housing Material: Cast Iron with Aluminum Cover
- Pinion Flange: 93mm Bolt Circle
- Driveshaft Pilot: 110mm
- Fitment: Independent Rear Suspension (IRS) equipped Mustangs
🔧 Fitment & Compatibility
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2019-2020 | Ford | Mustang | Bullitt |
| 2024-2025 | Ford | Mustang | Dark Horse |
| 2024-2025 | Ford | Mustang | Dark Horse Premium |
| 2015-2025 | Ford | Mustang | EcoBoost |
| 2015-2025 | Ford | Mustang | EcoBoost Premium |
| 2015-2025 | Ford | Mustang | GT |
| 2015 | Ford | Mustang | GT 50 Years Limited Edition |
| 2015-2025 | Ford | Mustang | GT Premium |
| 2021-2023 | Ford | Mustang | Mach 1 |
| 2016-2020 | Ford | Mustang | Shelby GT350 |
| 2016-2020 | Ford | Mustang | Shelby GT350R |
| 2020-2022 | Ford | Mustang | Shelby GT500 |
| 2015-2017 | Ford | Mustang | V6 |
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