1975 Dodge Dart Rearend Swap - Size Does Matter

Who says you can't find usable parts at salvage yards and swap meets anymore? Sure, it may be harder than it used to be, and you sure as heck won't find a 426 Hemi resting in a Road Runner in a salvage yard, but sometimes you can stumble across some parts you know you will be able to use someday.

When we started to resurrect our '75 Dart Sport, we knew it needed a lot of work, and we wanted to put the car on the road with as little money as possible. We first made it road worthy, which cost us $810. Driving it was cool, but it still didn't look cool. So we painted the wheels, added a set of tires and "dog dish/poverty" caps to our painted wheels, put an OE-style wing on the trunk lid, and an A-Body scoop on the hood. This brought our total to $1,872. Now it finally looked cool, but it really didn't sound the part. So, for an additional $2,149, it sounded the part with a V-8 swap. This brought our total to $4,021. Now I don't care who you are, building a good-looking driver for under $5,000 is tough . . . but fun.

There were a few things we felt we should address, if for no other reason than safety's sake. The Sport came from the factory with 9-inch drum brakes all around, and stopping was neither quick nor pleasant-it was a planned attack of excitement, especially in traffic. There are many companies that offer disc-brake conversions, and some are even "economically" priced. But what if you just can't spend the money needed to get a new kit? There are things you can do if you're willing to spend a little time looking and some elbow grease after you find what's needed.

To do the front-end swap, you'll need the spindles from a '73-and-up A-, B-, E-, F-, J-, M-, or R-chassis disk-brake car; drum spindles don't work for an OE swap. You'll also need the rotors, calipers, and caliper brackets. There are two types of calipers: pin-mount style and slider style. Don't forget to also grab the prop valve.

We were fortunate enough to find a mid-'70s B-Body that had just been brought to the local salvage yard and were able to grab the entire disc-brake setup for $50. We simply unhooked the ball joints, cut the rubber hoses, and removed the prop valve. Some of the parts from the scavenge will not be used, but when buying new calipers, for instance, there was a $15-per-caliper core charge when we got the new ones. Having the old ones to hand in saved us $30. By the time we walked out of the local auto parts store, we had spent another $245 for a new master cylinder, bearings and seals, calipers, brake pads, rotors, and brake lines.

There has been a fierce debate over the use of the later B-, F-, M-, J-, and R-Body spindle. Switching to the later B-Body spindle actually gives you more stability, as the Steering Axis Inclination (SAI) is 8 degrees as opposed to the A-Body's 7.5. If you are really interested in the entire story about brake-spindle swapping, check out Mopar Muscle's March '05 issue. Bill Reilly of Reilly Motorsports (reillymotorsports.com) scientifically proved its worth.

So now we had everything needed to handle the front end, but what were we going to do with the rear? We didn't want a big bolt-pattern wheel on the front and a small bolt pattern on the rear. Not only that, the 7 1/4 rear was already making noise from the V-8's, err maybe it was the driver's abuse. trying to find an A-Body 8 3/4 rear for cheap is not going to happen, but a possibility is finding an 8 1/4 rearend. The 8 1/4 came in a lot of A-Bodies, and unless you plan on continued racing abuse, it can serve as a good economical rearend for your driver.

Luckily, we had a friend who just happened to have an 8 1/4 that was in his way, and he offered it to us. We know what you're thinking, Like anyone is going to give ME a rear for my car. Ok, so in order to be fair, we'll say a good 8 1/4 rearend could probably be had at a swap meet for about $150.

But now a really big problem has arisen-the wheels won't fit!