Jeff Strange of Strange Engineering
The next time you think you're having a bad day, be thankful you're not a rearend. In an era when anyone can build a 500hp small-block and have DOT-approved tires and cut sub-1.5-second short times, rearends endure a brutal existence. Fortunately, the days of scouring junkyards for a dwindling supply of factory 12-bolts are just about gone. With the aftermarket stepping up with quality rearends built entirely from scratch, hot rodders have more options than ever when it comes to driveline fortification.
Leading the charge in ensuring driveline reliability in your street machine is Strange Engineering. For more than 40 years, Strange has been a premiere manufacturer of quality aftermarket rearend and suspension components for applications ranging from street cruisers to professional drag-racing chassis. With bolt-in housings and rearend components for A-, F-, and G-bodies, Strange has the Chevy camp thoroughly covered. Although driveline parts haven't changed much in outward appearance since the '60s, the technology and manufacturing techniques that go into them have evolved dramatically. To get educated on these advances, we sought the expertise of Strange's Jeff Stange. Here are his tips on components selection, how to avoid common problems, and putting your money where it counts.
Junkyard Vs. New
Used rearends are often more than 20 years old and have seen a fair amount of abuse-not necessarily desirable in a performance upgrade. In addition to saving you the time and effort of digging in junkyards, another key benefit of aftermarket rearends is that they address the weak points of factory designs. "Our 12-bolt and S60 bolt-in rearends feature full 360-degree welds at the tubes and nodular iron or chrome-moly differential caps," says Jeff. "New rearends also feature 3.150-inch bearing and 1.5635-inch axle bearing surfaces, far superior to factory GM specifications. The castings we use for our 12-bolt and S60 rearends are cast from premium nodular iron and were designed to be more rigid through the use of computer modeling for improved durability and quieter and longer-lasting gears."
For many Bow Tie fans, brand loyalty takes a back seat to practicality when opting to run a 9-inch rearend. One of the 9-inch's benefits is the vast array of parts to chose from, but that can also add confusion to rearend building, especially when it comes to third members. Factory 9-inch cases were manufactured from gray iron and nodular iron. According to Jeff, nodular iron is 50 percent stronger than gray iron, which is a very brittle material. Junkyard 9-inch cases are very difficult to find these days, and he advises against using a non-nodular case for any of today's applications. "OEM nodular cases, which have an 'N' cast onto them, are fine for street cruisers but not for race cars," he explains. "All our iron cases are cast from premium-grade nodular iron and manufactured by us in the United States. There is no point in manufacturing an aftermarket case from gray iron or other inferior materials, when nodular iron increases strength by 50 percent and is far more ductile. Strange offers two types of nodular iron cases: The S-Series nodular iron case is recommended for applications up to 850 hp, and our Pro nodular iron case can be used on applications that exceed 850 hp."
There is a time and place to use aluminum in a street machine, but a rearend isn't one of them. Aluminum cases are hot in the street rod scene for aesthetic purposes, and they are plenty adequate for many moderate-horsepower street vehicles. However, other than looks, an aluminum case really has no benefits. "A nodular iron case is a much better choice for street use, and the weight break with aluminum is negligible," Jeff explains. "For a musclecar weighing more than 3,000 pounds, a nodular iron case provides a much better foundation for the rearend assembly. Compared to aluminum, a nodular iron case will provide longer gear life and quieter operation."