Crate engines continue to grow in popularity because you know exactly what you’re going to get, how much it will cost, and (usually) when it will ship to your door. Strange Engineering has taken a similar approach with its bolt-in rears.

Strange Engineering can sell you a complete 12-bolt rearend for your third- or fourth-gen Camaro or Firebird. It’s way beefier than the stock piece, and dollar for dollar, it is more cost effective than trying to upgrade your stock piece.

Few things can be as frustrating as dropping parts off at a machine shop, engine builder, or any high-performance depot, then waiting months or even years for your work to be completed. It’s one of the many reasons, including price, that Strange’s bolt-in rears have become so popular. The prices are right, you get 100 percent new parts, and its reputation for quality is well-known in racing and hot rod circles.

Long Ago In A Muscle Car Far Away …

Once upon a time, you could buy a muscle car with a 12-bolt, 9-inch or 8 ¾ rear and beat the heck out of it. Then came the mid ’70s and horsepower dried up, along with most of those indestructible parts. Rear-drive vehicles were still made — think third- and fourth-gen Camaros and Firebirds, trucks, etc., but gone were the driveline parts that you could hammer on with impunity, or use as the basis for a mega-horsepower build..

Now that building huge power is as simple as going online with your credit card and muscle cars of the ’60s are selling for impossibly high prices, enthusiasts are left with the option of buying an import, a motorcycle, or sticking with a more modern V8/rear-drive vehicle, perhaps one of those F-bodies or trucks mentioned above.

The problem is not a lot of good upgrade parts are available for their factory rearends.

This is the S60 bolt-in rear for the third- and fourth-gen F-bodies. It’s shown here with optional caliper mounts and black powder coat finish. The fourth-gen unit has provisions for anti-lock brakes.

This is where the bolt-in rears are a smart choice. Why bother upgrading your 10-bolt rear, for example when you can get an entirely new built unit for about the same price? Or, let’s say you are starting with a third-gen Camaro or Firebird, which were notorious for weak rears. Strange Engineering of Morton Grove, Illinois, has great solutions.

“So, our bolt-in 12-bolt we typically recommend up to around 700, 750 horsepower,” said J.C. Cascio, Director of Business Development for Strange. “Once you start getting beyond that, then you have some limitations with the rear. With the 12-bolt with a Posi, the largest spline axle we can do is a 33, however something that is street driven with moderate horsepower, the 12-bolt is fine. It reuses the factory driveshaft. We supply it with a conversion U-joint to adapt that. It accepts the factory brakes so they’ll accept the factory ABS options, if the car has that, like a fourth-gen [F-body].

“If it’s something that is going to be raced — even casually — we would really push towards the S60 version [a Dana 60-style rear],” Cascio continued. “The cost is about the same, but you get a 35-spline axle with the S-Track, our helical gear-style Posi, so that’s a great all-around unit, whether it’s for street, road race or drag race.”

One benefit to the design of these S60 housings is all the factory brakes will swap over. The only catch with that is that the S60 — the Dana 60 pinion — sticks out further than the 10-bolt, so the driveshaft does need to be shortened or replaced.

“But usually if somebody’s that far into a build, that’s not an unreasonable upgrade for them to do,” Cascio said.

To be clear, the 12-bolt will handle race duty and autocross stuff, etc. The big benefit to the S60 is the ring-and-pinion Stange uses are Dana Spicer parts, an OE-type gear, so the setup, strength, and noise is a bit better than the 12-bolt style. If you have a third-gen and you’re retaining the factory torque arm or are using solid or polyurethane bushings, there may be less noise and harmonics resonating their way into the vehicle with the S60.

“The S60 is definitely a better option from that standpoint,” according to Cascio. “There’s really no downside to them other than the driveshaft thing.”

From a price standpoint, there is virtually no difference between the bolt-in 12-bolt and S60.

At this writing, the S60 starts out at $3,364, while the 12-bolt is $3,395. If you are someone who would prefer to keep your GM car all-GM and not use a Chrysler-style rear, the bolt-in 12-bolt should be more than enough for your street car.

The S60 is Strange’s version of the Dana 60 that came in ¾-ton Dodge trucks starting in 1961 (some even earlier), and was standard equipment in all Hemi- and 440-power Dodge and Plymouth muscle cars with a four-speed starting in 1966.

Strange does its own casting of this rear, but it has a provision for the torque arm built into it. It takes all Dana 60 internals, but for cars originally equipped with three-channel ABS, it has the bung cast into the top, so you can put the factory ABS sensor in there if you are building a fourth-gen.

Trucks Are The New Muscle Machines

For a variety of reasons, hot rodders — like new vehicle consumers — are more often turning to trucks for their creations. If you are looking in their direction, Strange has bolt-in rears that will save you the hassle of building something.

This is Strange’s bolt-in S60 rear for a 1963-’72 Chevrolet C-10 truck. It also has a unit ready to go in the ’73-’87 C-10 (not to mention K-10, Blazer and Suburban. These use 35-spline alloy axles and Trac-Lock differential.

Let’s say you have a 700- or 750-horsepower engine in your Chevy C-10. For you, Strange offers bolt-in S60s or 9-inch-style rears.

“We don’t even do a 12-bolt for those, the C-10,” Cascio said. “For those, we do an S60 or 9-inch Ford for those. Again, if it’s just a street driver, I usually like the S60 because it’s a 9 ¾-inch diameter ring gear, it’s got 35-spline axles right from the get-go. It’s a bulletproof kind of rear you bolt in and forget about it.

“If it’s something where you know you are going to race it, say you’re doing drag and drive-type stuff, and you might carry a couple of different gear ratios, that’s where the 9-inch truly helps out because you can pop the centers in and out a lot quicker. You’ve got a fabricated housing, so some people like the look of that as well.”

What applications are available? Strange has every C-10 from 1960 to 1987 covered.

“You could easily spend two grand just on parts, and then you have labor involved, so you’re getting pretty close in price with just a rebuild,” according to Cascio.

When discussing the 9-inch rears, pricing gets a little more complicated to piece together because there are so many options with the 9-inch.

“Just the fact that the 60s are packaged a little bit better because you know what they are,” according to Cascio. “The housing is the housing, whereas with the 9-inch you have the standard housing or fabricated housing, modular centers, aluminum centers, different types of posis, different spline axles, so the 9-inch rears get a little more involved to quote out.”

This means the 9-inch rears can be more money, but it really all depends on options.

Chances are Strange has a bolt-in rear for whatever you are building. Here is its S60 for a ’64-’74 Barracuda.

While this story covers the bolt-in rears for third- and fourth-gen Camaros and C-10 trucks, Strangs has a lengthy application for other vehicles as well: vintage Fords and Mustangs, Mopar muscle cars (A- , B- and E-bodies), to Buicks, Oldsmobiles, and virtually every Chevy known to exist. Click here to see its application guide.