F-Body Torque Arm
"Moser Engineering is now offering a performance chrome-moly adjustable torque arm for '82-92 F-bodies. The new unit fits existing 75/8-inch rearends in addition to stamped 9-inch and 12-bolt housings from Moser and many other manufacturers. One of the nice things about being a rearend manufacturer is that we've seen lots of different torque arms and suspension upgrade kits, which gives us an excellent perspective on how to create the best torque arm design. Our torque arm was patterned after the same type of setup used in Pro Mod cars and is intended for cars running 10s and quicker. Features include 11/4-inch chrome-moly construction, TIG-welded joints, and a sliding front mount to prevent bind and maintain excellent handling."
When flipping through the drivetrain section of a parts catalog, the difference in pricing between street and race ring-and-pinion sets is dramatic. So what's the difference between the two? "A street/strip gear is generally made from a harder 8620 material, while a race gear is made from a softer 9310 alloy," explains Moser. "In a race car, the softer compound is designed to absorb the shock load from a high-horsepower launch without fracturing. Most manufacturers advise against running race gears on the street because they wear much quicker than street/strip gears and cost almost twice as much. Generally, the launch characteristics of a car that requires a race gear are not going to translate to a car that will be driven on the street anyway."
M9 Fabricated Housing
For cars that have enough power and hook to flex and distort a standard stamped steel 9-inch housing, a fabricated unit may be the answer. They're made from a single piece of triangulated 1/8-inch laser-cut steel and feature internally welded gussets, bulkheads, and a 3/8-thick faceplate. "We have actually used the M9 housing design as the basis for our new full-floater housings that are being used in classes like Pro Mod and Top Dragster, where guys are going over 215 mph," says Moser. While fabricated rearends were once exclusive to full-tilt racecars, Moser offer its M9 housings in bolt-in form for street cars as well. "Not only do they function extremely well, but they also look great under the back of a street car. Even if you don't really need it now, it does lay the foundation for the future needs of the car as the horsepower grows. The M9 housing is priced so that there isn't a huge difference between it and a standard stamped housing, and if you add a back brace it makes for a very rugged setup."
12-Bolt or 9-Inch?
No interview with a driveline manufacturer is complete without stacking the best from Chevy and Ford against each other, so here is Moser's take on the matter. "The 9-inch is a bit stronger than a 12-bolt, has a larger ring gear, can accept 40-spline axles for extremely high-horsepower applications, and is easier to work on due to its drop-out center section," he explains. "However, the 12-bolt is about 2 percent more efficient, usually a little lighter, and more compatible with late-model GMs that have ABS. In most cases, both rearends are more than capable and it is really a matter of personal preference. While this debate will never end, the most important issue is that both designs are still being updated. Fabricated 9-inch housings are now available in bolt-in form for street cars, and it's now possible to fit 35-spline axles in a 12-bolt."