One of the odd things about pre-'72 Mopar A-Bodies was the use of five lightweight 7⁄16-inch wheel studs on a small 4-inch bolt circle. While Chrysler used the common 4 1⁄2-inch bolt pattern and beefy 1⁄2-inch studs on virtually every other car line (the early Imperial's 5 1⁄2-inch pattern being a notable exception), the early A-Bodies were saddled with an econo-box wheel pattern. Going back in the genealogy to the A-Body's origins, as Chrysler's compact economy entry in the early '60s, the five-on-four pattern didn't look so bad compared to the competition's compacts, which usually sported even more miserly four-bolt patterns.

In terms of function and durability in a stock vehicle, the smallish bolt pattern really presents no problems. The hang-ups begin when modifications to the factory package are thrown into the mix. Want to upgrade from the skinny, factory-fitted 13- or 14-inch wheels? Sorry, dude, the oddball "five-on-four" pattern has been all but forgotten by the aftermarket. If large modern rubber, or a serious set of drag slicks, are part of the plan, shelling out for special-order, or one-off modified wheels are about the only option if the stock small pattern is retained. Even then, if the wick has been turned up enough to produce serious dig off the line, you have to ask yourself, "Are those puny wheel studs up to the task?"

In 1973, the big-bolt pattern was finally made available on disc brake-equipped A-Bodies. Previously, the disc brake option consisted of the small-bolt pattern Kelsey Hayes four piston fixed caliper brake set-up, unique to the A-Body car line. The "new" brake set-up brought in for '73 was basically an adaptation of existing large-car components to the diminutive A-Body line. With the large car disc brakes also came the "big car" five lug on a 4 1⁄2-inch bolt pattern, and stout 1⁄2-inch wheel studs. Of course, to go with the large pattern up front, the rear was also revised to include the same large bolt pattern, as well as off-the-shelf "big car" drum brakes, replacing the skinny rear binders previously used exclusively in A-Body applications.

The new '73-and-up large-pattern A-Body rear brakes, B-, C-, E-, F-, J-, M-, and R-Body, as well as 1⁄2-ton light truck rear brakes as fitted to 8 1⁄4-, 8 3⁄4-, and 9 1⁄4-inch axles all interchange. The most common sizes of the big-car brakes were 10x2 1⁄2-inch and 11x2 1⁄2-inch and, with the exception of different parking brake cable lengths, are a bolt-on with any of the above mentioned rears. Of the A-Bodies produced after the change-over in 1973, the vast majority were disc brake-equipped, making the late-style brake hardware a very popular swap in earlier A-Bodies.