September 26, 2005

Big 9-Inch Options
Ford's super-durable 9-inch differential was the company's first removable carrier rearend when it debuted in 1957. The 9-inch Ford, named for its 9-inch ring gear, has been the industry standard for performance rearends for five decades. In NASCAR, the Ford 9-inch is the only rearend anyone runs, including GM and Chrysler. Currie Enterprises has made the 9-inch Ford something of an institution, offering a variety of 9-inch designs for many uses and budgets. Let's take a look at what will fit your lifestyle and budget.

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Ground Power
Building the right 9-inch Ford for your project begins with a solid foundation (the gearcases just mentioned). There's an array of gearcases (also known as chunks, pumpkins, third members, differentials, and more) to fit a variety of budgets and missions. Your budget, expected mission, and the amount of power your engine makes determine choice.

If you're seeking a limited-slip differential with nice street manors, the Currie Trac Lock is perfect for your Ford street project because it uses clutches to equal the distribution of power to both wheels. Available for both 28- and 31-spline applications, the Currie four-pinion Trac Lock is designed primarily for Ford 9-inch castings. You may also run the Trac Lock in a Currie 9-Plus. Currie Trac Lock: $399.95

When it comes to differentials, there's a whole lot more going on inside the gearcase that mandates good, solid decision making during the planning stages. Noise and erratic operation make locking differentials a bad idea for the street. Every time you turn a corner, locking differentials rear their ugly heads with a lot of noise. This is why limited-slip differentials make more sense for street use.

Most limited-slip differentials use internal clutches, which slip quietly in the turns. Choosing a carrier also depends on how much power you intend to throw at it. Limited-slip carriers have their limits before horsepower and torque rip them to pieces. Each manufacturer will tell you the limits of a particular carrier. This isn't everything that's available from Currie, but here are some of the highlights.

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