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Thought I would share some pics of my 9" rear end bui9ld up. Did not include all details, so please feel free to ask questions. My project car is a 1970 Mustang Convertible. The powertrain is a 351 based 393 Stroker with a C6. I decided to put together my own 9" rear and brakes. My wish list was as follows: Big bearing ends Axle length and axle flange dimensions compatible with modern rear disc brakes Stock width for the axle housing, and stock dimensions for spring perches Black satin powdercoat Posi 31 spline center section with 3:25 gear ratio 31 spine axles with sealed bearings Made in the USA So, my search led me to Iowa and Quick Performance (aka QP) , who supplied me with the heavy metal for the project. I also sourced some original 2004 Mustang Cobra brakes from an Ebay seller, and the brackets from Mustang Steve. I will attempt to lay out my assembly as best I can with some pictures.... Here is the axle housing assembly. The dimensions were perfect. Here is my redneck axle housing support, so I can work on this thing without hurting myself....(just the center section weighs like 85 pounds) The "big bearing" ends were used on the large cars like the Torino's. I wanted to use these and the larger axles, so QP said that this was no problem and made me one. Here is the end view. The furthest machined area is for the axle seal. The sealed bearing rear ends use this to prevent the rear end gear oil from leaking over to the bearing area. There are other big bearing rear ends that use tapered roller bearings where they need to be lubricated. I did not use that approach. The next machined area is for the bearing retainer to sit in. You will see this in my other pictures. The retainer is pressed on and keeps the sealed bearing in place, and locates the axle in the proper position. The outer machined area is for the bearing itself. When properly seated, the bearing will stick out a small amount. With my setup, the Mustang Steve bearing retainer plate will have a small machined out area to accommodate that. Next, I will show the axles. These are 31 spline with the bearings and retainers mentioned earlier. They are different lengths. You can see the lengths and diameter written on the axles in the pictures. DO NOT use these dimensions for your car. Make sure you ask you rear end expert, or if replacing stock axles, use one of the many references available to guide you. Note in one of the pictures I have my brake rotor installed on the end of the axle I used the Mustang Steve retainer plates and caliper mounting brackets. They fit perfectly. I made a decision to have QP make the axles and press the bearings and retainers on at their shop. The issue this creates is that the bearing retainer plate is supposed to be between the axle flange end, and the bearing. So, I had to modify the Mustang Steve bearing retainers by cutting a notch in them to allow me to slip them over the axles. This is very typical of other bearing retainer plates. The process to do this is a "measure twice, cut once" approach. The retainer plates only will work on one side (left-driver, right-passenger). Mustang Steve provides a lot of holes to handle a variety of applications, and it worked out. In the pictures you will see the bearing retainer plates, and one smaller plate, which is what the Cobra caliper bolts to. There is also a close up that shows the "inside" of the bearing retainer bracket with the machined out area to accommodate the roller bearing protrusion. ' Next, I will show the center section. I chose to use 3:25 gears on this car, as it will be more of cruiser than a drag racer. My tires will be 25.7" tall, and with the C6, 3rd gear has a 1:1 ratio, so that puts me at around 2600 rpm at highway speeds. I will be using a TCI streetfighter converter with a nominal flash stall of around 2000 rpm, so that will be a good combination for my needs. I chose to use a Nodular Iron center section with a Daytona Pinion. QP builds these in house and runs them in before shipping them out. It is a beautiful piece. I chose to clear coat it, as I was not interested in the "red oxide" look. QP provided the studs for mounting of the center section, along with nylock style nuts. The center section had machined surfaces where the nuts would sit, so I did not use washers. The original Ford castings were rough, and the factory used copper washers under the nuts. Most of those are long gone.... I used a spacer/washer, and a Grade 8 nut to pull the studs through. Don't use an impact wrench, you could crack the housing or damage the stud. I did not take a lot of pictures of the next steps, as my hands were pretty busy.... Next steps: RTV on the axle housing, then set the stock gasket on the housing. Then, put a thin bead of RTV on the gasket. Set the housing slowly (it is heavy) on top of the studs. Keep a mallet and a wooden block handy, as you may need to coax the housing over the studs. Torque them down (I think around 40 lb-ft, but check that). The lower 2 bolts require an open end wrench to tighten. Install the axle seals. You will need a big socket (1-1/16) and some patience. Keep the socket square. Keep the flat part of the seal facing outwards. Tap/hammer/coax the seal in until you feel resistance (metal to metal). If you pound on the seal, you will be buying a new one.... Coat the rubber part of the seal with lithium or axle grease. Coat the axle surface inboard of the retainer ring (this is where the axle seal will ride) with grease. Apply a thin coat of RTV to the outer machined race in the axle housing (this is where the bearing sits) Hold the axle straight and insert into the housing, taking care not to put too much pressure on the axle seal. (this is kinda like installing a camshaft and not wanting to damage the cam bearings) When you feel the axle engage with the center section, turn the driveshaft yoke to try and seat the axle. Then, take a block of wood, and gently tap the axle into place. The sealed bearing will just stick out maybe a 16th of an inch when you are done. Use the "T-bolts" to install the Mustang Steve bearing retainers, and tighten them down. Torque on these is around 35 lb-ft (check that). You will need a 3/4" short socket to sneak under the axle flange, and will need to line up the hole in the axle flange to get your torque wrench extension through the hole. Next comes mounting the brake calipers. Attach the Mustang Steve caliper mounting bracket. Note, that in my case, there is a spacer that they provided that is inserted between the bearing retainer plate and the mounting bracket. This is necessary to get the correct offset for the caliper, and to center it over the rotor. I am using NOS Ford Racing slotted and drilled rotors for my rear brakes (11.5"). I know I skipped a lot of steps, but I hope the pictures helped. I am very happy with the Quick Performance products I received [i have no affiliation with them, so I am just passing along their information for others to decide for themselves, but I was thrilled to find a heartland company with great products and great customer service]. ​​I am also very happy with the Mustang Steve products I received. I have no affiliation with them]