An aftermarket rearend is a must-have item when if you decide it’s time to start making serious horsepower, or just want to upgrade to a more reliable setup. There are plenty of aftermarket rearend options out there, and Strange Engineering makes it easy to select the right unit for your ride thanks to its numerous bolt-in rearends. In this article, we’re going to cover the rearends Strange offers, and what options you can equip them with.

Strange has a wide range of products in its catalog from your basic OEM upgrade 12-bolt rearend, all the way to full-floater units that can handle upwards of 11,000 horsepower. We’re going to concentrate on the rearends that will bolt directly into a vehicle. The offerings from Strange that fall within that spectrum include a Ford 9-inch, the S-60 (Strange’s version of the Dana 60), and the 12-bolt rearend.

Bolt-In Rearends

The Rear End Application Guide on Strange’s website shows just how robust the company’s bolt-in rearend selection is. There’s a tab for Ford cars, Ford Trucks, GM vehicles, and Mopar vehicles. You can also see which rearends are offered for each vehicle.

Strange wanted its bolt-in rearends to fit like an OEM unit, so they put a lot of effort into how each rearend was designed. J.C. Cascio from Strange Engineering explains how the company approached the process of creating bolt-in style rearends.

“All the bolt in rearends we offer are built using a specific fixture for that particular vehicle. Whether it’s a Fox Body, G-body, C10 truck, or other vehicles, they all have a fixture. We start with a factory housing and build a fixture around that. Every bracket is in the factory location, so all the geometry stays the same. The S-60 rearends might have some tabs in different locations, that’s because it’s a larger casting, but for the most part, the geometry of all the brackets is the same.”

Selecting the right rearend comes down to the application, horsepower is just a part of the equation, it’s not the defining factor, – JC Cascio with Strange Engineering

For certain applications, Strange adds extra lower control arm bracket options on the rearend. These rearends give the user the ability to change the rear suspension’s geometry based on how they use the vehicle. So, those who drag race or autocross can make adjustments without having to worry about adding additional brackets to the rearend.

“We actually designate where the OEM holes are on our rearends when there are multiple adjustment options to make setting up the suspension easier. This eliminates the guesswork for customers and gives them a baseline to set the vehicle up. It’s like having an OEM rearend with even more adjustment options,” Cascio states.

How To Select The Right Rearend

Let’s face it, those who modify cars love to have tons of choices when it comes to how they can configure something they plan on bolting to their vehicle. The problem is, sometimes you can easily get lost in the weeds when trying to figure out what options will work for your vehicle. Not everyone uses their vehicle the same way, so there’s no-one-size fits all option for a rearend.

Thankfully, Cascio and the team at Strange can help anyone figure out which rearend will work the best for their vehicle. Cascio explains how Strange walks customers through the rearend selection process.

“The first thing we would do is look at the application. We need to know what the vehicle will be used for since drag, street/strip, autocross, and only street use are different. That would let us know what options they’ll need like axles, differential, brakes, and such. We need to know the weight of the vehicle, horsepower, and torque. If the vehicle is going to see time at the drag strip, we’d need to know the type of racing, the tires, and if a transbrake is going to be used. There are lots of things that factor into picking the right rearend.”

Now, many people think that horsepower is the ultimate factor you need to consider when buying an aftermarket rearend. Cascio is quick to point out that the amount of horsepower your vehicle makes is just a starting point, and going off of the horsepower number isn’t enough. You need to consider the weight of the vehicle and really build a complete picture of how it will be used. Think about it, a vehicle that’s making 800 horsepower and weighs 2,800 pounds is going to need a different rearend than a different vehicle that’s making the same power but weighs 4,000 pounds.

The Strange rearend will arrive ready to bolt in, you’ll just have to add fluid and plumb some brake lines.

“The 9-inch has so many options and that makes it attractive for many people. From the housing to the center section, you can really customize it for your needs. If it’s something they’re going to bolt in and not worry about, the 9-inch and S-60 are their best bet. If someone is looking to use the vehicle in performance applications, I tend to recommend the 9-inch rearend. That rearend lets you change gear ratios quicker and it’s easy to service,” Cascio explains.

While the 9-inch is Strange’s most popular rearend, the S-60 is a close second thanks to how Strange designed this unit. These rearends have a beefy ring and pinion gearset that can take plenty of abuse. You’ll also find massive modular iron caps, and a ridged one-piece center casting has been incorporated into the S-60. These features make the S-60 a great choice for people who plan to put a lot of miles on their vehicle, and who still want to enjoy worry-free trips to the drag strip.

The 9-inch has so many options and that makes it attractive to many people – JC Casico

“The S-60 is easier to work on than a Dana 60 thanks to how we designed the casting. It has adjuster nuts incorporated into it, so you can adjust the backlash and preload on the differential easier versus the OEM way of doing things. This appeals to people who want something that’s simple to bolt in and not have to worry about how strong it is,” Cascio says.

Strange’s GM 12-bolt rearend is geared towards the leaf spring vehicles, as well as third, and fourth-generation F-bodies. The 12-bolt rearends are available in numerous configurations with different axle, cover, and differential options. You can order a custom width 12-bolt rearend based on your applications and outfit it with specific housing ends, pinion offsets, axle flange diameter, and other options.

Rearend Options

So, you’ve picked out a housing that will work best for your vehicle, now it’s time to start adding options to your Strange rearend. The options you choose should be geared toward how you’re going to use the vehicle. This is where contacting the experts at Strange will pay big dividends, they have years of experience guiding customers to the best rearend for a specific application.

The 9-inch rearend has more options compared to the S-60 and 12-bolt rearends. This is one of the reasons it’s Strange’s top-selling rearend.

“With the 9-inch, you can select the standard heavy-duty housing or the Ultra Fab housing. That choice is usually based on how the customer plans to use the vehicle. Some need the Ultra Fab for its strength, others want it for the look. Then we look at the center section and that’s where the options open up.  You can choose from a standard case, nodular case, aluminum case, throughbolt aluminum case, pro iron case, and several others. Next, we look at the type of differential the customer will need. If it’s a drag car you’d use a spool, a street/strip would need a Strange S-Track or Detroit Locker. For all-purpose vehicles that don’t see the track, we’d look at the 31-spline Truetrac. It’s good for everyday driving,” Cascio says.

But wait, there’s more!

“After we have figured out the differential, you’ll need, it’s time to move on to the axles. The standard alloy axles are perfect for street/strip and general driving applications, while the Hi-Tuff axles are what we recommend for drag racing applications. Then we’d look at brake options. We can set the rearend up to cover most OEM options, so you don’t need to purchase the rearend with brakes. We also can set the rearend up for our Strange drag brakes, Wilwood street brakes, or drum brake options as well,” Cascio states.

There’s a lot that goes into picking out Strange 9-inch rearend. The 12-bolt and S-60 rearends have their own options that you can select and they are both very similar.

“The S-60 doesn’t have as many options, but there are some upgrades and changes you can make. It comes with 35-spline axles. It comes with a 35-spline Traction Lock which is a clutch unit but can be upgraded to a Truetrac, full locker, or spool. It comes with the 35-spline axles and makes it a great overall option, especially for the street/strip people,” Cascio explains.

As you can see, Strange Engineering has a rearend for just about every automotive application you can dream up. The best part is, there’s a good chance they have a rearend that will bolt right into your vehicle.