Today's Mopars are packing some serious power and need a strong rear axle to survive. With big-block Chryslers thundering horses from 500 inches or more, the once reliable 831/44 rearend is probably not up to the added abuse. Sure, you can spend a lot of bucks and retrofit your 831/44 to take more punishment or search the swap meets for an old Dana, but the cost of replacing the 40-year-old bearings, axles, Sure Grip unit, and gears will be expensive.
Well, the guys at Strange Engineering have a solid answer for you. They've released a brand-new bolt-in rearend for your A-, B-, or E-Body Mopar called the S-60, and although it looks much like the original Dana 60, it's even better. For about $1,850, the S-60 assembly includes Strange 35-spline S/T (Street and Track) axles, a 9.75-inch ring gear, a Trak-Lok differential unit, your choice of gear ratios from 3.54 to 5.87, a 1350 steel pinion yoke, a machined pad to accept a pinion snubber, and much more. And for you hard-core guys, Strange offers plenty of extra-cost options, such as Pro Race axles, Spools, Power Loks, and Detroit Lockers. Best of all, each S-60 comes delivered on a crate and ready to bolt in. Just order the one already sized and fitted for your popular Mopar.
To see how well this works, we decided to order a new Strange Engineering S-60 for a '63 Plymouth Belvedere that's slated for a 505-inch Mopar buildup. Since Strange Engineering's listings only go back to '66-'67 B-Bodies, we first wanted to measure our Belvedere to verify if the existing 831/44 rearend's dimensions matched the new S-60's measurements of 44 inches on the leaf-spring centers and 5411/44 inches on the outer housing ends. Years ago, we installed a '65 B-Body 831/44-inch rearend with flanged axles into our Belvedere and axed the '63's original and user-unfriendly 831/44 with press-fit hub and brake drums.
Our first rear suspension calculation confirmed that our '63's underpinnings (as well as all '62 to '65 B-Bodies) share the same 44-inch, center-to-center leaf-spring mounting span as the '66 to '67 B-Bodies. we measured the outer housing end-to-end (not the axle flanges) dimensions and discovered that the '65 831/44 totaled 5411/44 inches, just like the Strange S-60. Good news!
From the gear ratio choices offered, we selected a 3.54 cog for our 505-inch torque monster. Each S-60 also features big 3-inch axletubes that are fully welded 360 degrees into the iron center-section. The massive axles ride on 3.150-inch Timken axle bearings for additional strength. Strange Engineering also has a choice of housing ends to accept almost any brake configuration. If your budget allows, Strange offers a full line of rear disc-brake conversions kits or Ford-style rear drums. Since we already had a complete set of 11-inch Mopar drum brakes confiscated from a '70 wagon, we opted for the Mopar housing ends. To maximize our Belvedere's factory brake performance, we ordered a full set of Raybestos brake shoes, drums, and spring kits, as well as all-new, OE-style, hard brake lines from Classic Tube.
With a floor jack, some jackstands, and an air gun, we pulled the 831/44 rearend out and swapped the Strange Engineering S-60 in its place. With that completed, we added our 11-inch backing plates, Raybestos brake parts, and then installed the new Classic Tube hard lines.
The new S-60 install went great and looks pretty cool with its Dana 60 chrome cover. As we get closer to having our 505-inch Mopar off the dyno, we're looking forward to churning the horsepower through this new S-60.
To get one of these in your Mopar, all you have to do is install the Strange S-60 rearend, add gear oil, and fire your motor up. Think of it as a crate engine for your rearend.
B-Body Rearend Math 101
The S-60 selected for our '63 B-Body is marketed for '66-'67 B-Bodies, and measures 5411/44 inches from housing end-to-end (w/o the brake backing plates installed) with 44-inch leaf-spring centers (measured from pin-to-pin). We found these mounting points dimensionally the same as the '65-'67 Belvedere 831/44-inch flanged-axle rearend. Unlike the '65-and-later 831/44 rearends, the original '62-'64 Plymouth 831/44 rearends use cumbersome splined hub and brake drums.
The following chart is based on the dimensions and styles of B-Body 831/44 rearends from '62 to '67 with a center-to-center leaf-spring span of 44 inches. Remember, before you order any rearend, it's best to take a few minutes and take your own measurements to ensure rearend and wheel/tire fitment.
Year Axle flange-to-flange width ’62-’63 521¼4 inches ’64 541¼4 inches ’65-’67 541¼4 inches