Speedway Centered Housing Axle Kit, 56 Inch Width, Fits Ford 9 Inch

HEAVY-DUTY CONSTRUCTION: Fabricated steel center housing with reinforced 3\" O.D. axle tubes and internal bracing delivers superior strength and reduced flex vs factory housings, CENTERED HOUSING DESIGN: Pumpkin-centered layout with equal-length axle tubes simplifies suspension bracket placement for 3-link and 4-link setups. Housing measures 51\" from flange-to-flange. Total wheel-to-wheel mounting surface width is 56\" (from hub-to-hub)., HIGH-STRENGTH AXLES: Includes 31-spline alloy steel axles with bearings, seals, and retainers built to handle increased horsepower and demanding street applications. Includes one 33\" long axle and one 29-1/2\" long axle (axles are cut to fit), MULTI BOLT PATTERN FLANGES: Axles drilled for 5x4.5\", 5x4.75\", and 5x5\" bolt patterns for compatibility with Ford, G Speedway Centered Housing Ford 9 Inch Axle Kit, 56 Inch Width Sku # 91604090 Mfr. Part # 91604090 Condition New Brand Speedway Motors Sold Kit Details

Looking for a budget-friendly, rock-solid foundation for your custom rear suspension? Look no further. Our fabricated steel Ford 9 inch axle housings feature all-new components for maximum durability. It’s an evolution of the rugged and reliable 9 inch Ford platform.

Designed with the Builder in Mind

This housing is pumpkin-centered with uniform-length axle tubes, side-to-side. So mounting suspension brackets, especially on triangulated 3-link and 4-link systems, is much easier. Unlike factory stamped housings, these fabricated plate-steel center sections provide a wide, flat surface for easy bracket attachment. Note that the pumpkin-centered design will offset the pinion yoke about 1\" to the passenger side.

Axle tubes are 3” O.D. with a 3/16” wall thickness. Heavy-wall tubes, along with a larger center section, significantly reduce distortion during welding of rear-link brackets or spring pads. Billet steel “New Big Ford” (Torino) style bearing ends are fixture-welded (3.150” O.D. bearing, with 2.50” axle flange offset).

Improved Design for Greater Durability 

In addition to the heavy-duty bearing ends, the axle tubes are supported with bracing inside the large center housing. This reduces flex in the rear end housing, which is something you won’t find on stamped factory 9 inch housings. Plus, gears stay well-lubed and run cooler thanks to a large-capacity fabricated center (holds more gear oil than stamped housings). Axle is vented on the driver’s side.

Yet, with improved durability, our fabricated axle housing is on average 2 pounds lighter than stock style housings of the same size! Add your choice of axle shafts and third member (sold separately), and you are ready to roll. Equip your race car, hot rod or 4X4 with Ford 9 inch parts from Speedway Motors to ensure there are no weak links in your driveline combination. 

Total wheel-to-wheel mounting surface width is 56\" (from hub-to-hub). The pumpkin is centered in the housing, which puts the pinion 1\" offset from center, requiring different length axle shafts. This 56\" axle kit includes 2 cut to fit axles needing one 28-5/8\"\" long axle and one 26-3/8\" long axle. This housing includes (8) T-bolts for the axle bearing retainer plates and (10) studs for the third member.

Steel Axles

Our improved axle housings deserve equally strong axles to drive your street machine. Two axles made of alloy steel have the strength to handle the horsepower. Axles are 31-spline, includes axle bearings, axle seals, and bearing retainers. Flanges are drilled for both 5 on 4-1/2\" Ford/Mopar, 5 on 4-3/4\" GM, 5 on 5\" GM Truck wheel bolt patterns.

• Fabricated steel center section
• 3\" O.D. axle tubes with 3/16\" wall thickness
• Axle tubes are internally reinforced for additional strength, less flex
• Billet steel \"New Big Ford\" (Torino) style bearing ends
• Forged Steel axle, drilled for 5 on 4-1/2\" Ford/Mopar, 5 on 4-3/4\" GM car, and 5 on 5\" GM Truck Bolt patterns using 0.685\" knurl diameter
• Street application 1/2\" thread wheel studs sold separately 
• Accepts brake kits for 2.50\" axle shaft flange offset (from housing flange)
• Housing measures 51\" from flange-to-flange
• Assembled rearend measures 56\" from hub-to-hub (axle flange face-to-face)
• Includes one 33\" long axle and one 29-1/2\" long axle (axles are cut to fit)
• Improved housing design weighs approximately 2 lbs less than stock-style fabricated housings
• Centered pumpkin w/ 1\" offset pinion yoke for easy suspension mock-up
• Greater-than-stock capacity center section holds more gear oil and runs cooler
• Requires different length axle shafts, left/right
• Includes vent on driver side axle tube
• Includes studs for 3rd member and 3/8” T-bolts for bearing retainer plates
• 3rd member sold separately

For more information on determining the proper axle length and the Ford 9 Inch, be sure to check out our tech articles; Measure and ID Axles and Housings and 

Specs Sold in Quantity Kit MFG. Part # 91604090 Position Rear Overall Width 56" Axle Shafts Included Yes Axle Splines 31 Axle Type Semi-Floating Brakes Included No Third Member Included Yes Ring and Pinion Included Yes Wheel Studs Included No Wheel Stud Thread Size 1/2"-20 Wheel Bolt Pattern (in.) 5x4.5 in. | 5x4.75 in. | 5x5 in. Bearings Included Yes Seals Included Yes Differential Included No Material Type Steel Finish Natural Ring Gear Size 9 Inch Differential Type Limited Slip Tube O.D. 3" Housing Material Steel Hardware Included Yes Rotors Included No Rotor Diameter Not Included Housing Color Gray Cut to Fit No Standard Pinion Location Offset Pinion / Centered 3rd Member Bolt Pattern 5x4.5 | 5x4.75 | 5x5 Reviews Love'n a nice rear-end! Rated by Tom on September 04, 2025

Summary: I wasted so much time on my old one trying to narrow and de-rust. I didn't want to spend the money for a new one. That was a mistake. The new one has very nice and clean welds. The finished product turned out really nice.

Yes, I recommend this product.

Exactly as described. Rated by Suncoast Mack on June 30, 2025

Summary: Good weld quality, good steel to weld mounts to also. Very pleased.

Yes, I recommend this product.

Nice rear end for the money Rated by Jesse Rivard on January 30, 2023

Summary: This is a nice rear end however make sure to know what size to cut the axles at. I didn't know the axles would need cut. Not to bad of a job with a chop saw but definitely an extra step

Yes, I recommend this product.

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