[1]The Mopar crowd has a few choices when it comes to rearends for their musclecars, and what the factory offered can be a number of things. For Project Bullzeye, our 1971 Dodge Dart Swinger [2], the wimpy 7-1/4-inch differential was fine for a slant six, but pushing it for even the common upgrades [3] we did to the LA 318 small block.
[4]But, as all of our project cars are destined to be something other than stock, we needed to do some upgrading to the Dart. We have done a few engine mods, but knew that in the future the engine and trans were going to be tossed for a more potent drivetrain. In the meantime, we wanted to do some suspension and brake upgrades now so that any powertrain upgrade later wasn’t going to be at the expense of a wimpy differential.
We called on Strange Engineering [5] to get something up under this Mopar that will handle whatever future powertrain mods we throw at it. While the factory offers an 8-3/4-inch differential with a suregrip, finding one for our A-body Dart wasn’t going to be easy. We also knew that we would have to upgrade the bolt pattern from the smaller size to the more popular 5×4.5-inch. Then there were the brake upgrades we were going to do, also, before installing the American Racing Wheels [6] we decided upon.
[7]Checking out their website [5], we found the S60 differential from Strange and we knew that would give us a beefy rearend, and that it is built as a good Dana 60 replacement. Strange offers the S60 as a complete housing [8] with welded flanges and spring perches, as well as brake line tabs. These housings can be “made to order” in whatever widths you require, as well as perch width adjustments for relocated springs and tubbed cars. We had ours set up to fit the larger B-body brakes, which was a simple task for Strange.
Of course, that’s only part of the package that we needed, and we also included the S60 third member with 3.54:1 gears and complete axles from Strange, too. From spools to just about any third member you need, the options are available on the website. The S60 third member we went with is the 35 spline S-Trac [9] posi unit, which has helical cut gears for both strength and traction. This overall combination makes for a great street car that is going to also see some track action – perfect for our Dart. Finally, we finished off the rearend with 35 spline axles and had them installed and the complete differential and third member sent as a completed unit.
The alloy axles will provide the strength we need for the additional horsepower coming down the pike. For narrowed rearends, Strange can provide you with whatever lengths you need, with options for larger or longer studs if needed. The wrecking yards can provide you with a stock replacement, but Strange Engineering can hook you up with just about anything you need for your street car, musclecar or racecar, based on your dimensions.
Keep an eye out for our Project Bullzeye and the entire brake, wheel, suspension, and drivetrain upgrade in the coming months, and check out their website to see how they can help you get some Strange for your musclecar or racecar.
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