Budget g-machine Brakes for Musclecar Mopars

(Cordobas actually are good for something)

Written by Andy Finkbeiner

Photos by Ron Valera

One swap that is starting to gain popularity among Mopar owners is the use of later model disc brakes onto their classic musclecars. Chrysler might have made some of the most powerful engines during the musclecar years, but they certainly didn’t provide the brakes to match. Fortunately, there is a fairly inexpensive way to put the best factory brakes this side of a Viper onto your Mopar musclecar.

What makes this swap work is the fact that Chrysler engineers left the basic front suspension design alone from 1962 to 1972 on the B-body Mopars. In addition to that, they used a common parts bin solution for many years after 1972 in an effort to save money. The net result of this economizing is that we can now pick and choose the best factory parts and have them all work together.

The swap which we’re detailing in this article shows how to adapt the big 11.75 inch rotors from the late model Cordobas onto earlier musclecars. This swap will work on most any A, B or E body Chrysler product produced during the 1960’s and into the early 1970’s. There are several different variations depending on the particular year and model of the car being worked on which we can’t go into in this article, so you’ll want to check out one of the reference books before getting too deep into your project.

For those of you new to the Mopar world, A-body refers to the smaller line of cars such as the Duster, Dart and Valiant. B-body cars are the mid size sedans such as the Coronet, Charger, Belvedere and Satellite. The E body cars are the good looking Cuda’s and Challengers built from 1970 to 1974.

So follow along as we bolt some big factory binders onto a 426 powered 1965 Dodge Coronet. Just for fun, we’ll add some twists to our swap that not very many people have seen before. Once you get your project all back together you should spend some time in a parking lot getting used to your new brakes and adjusting the proportioning valve. Good luck and happy stopping!

Tom Condran and Frank Adkins have both written excellent books on upgrading musclecar Mopars. These reference books will help sort out some of the potential complications on this swap which certain years might have. You should also always have the correct factory service manual nearby before attempting important work such as suspension and brake modifications.

This steering knuckle is the key to the whole swap. These disc brake knuckles with the big bearing spindles came only on the 1973 to 1976 A body cars. Figure on spending about $50 for the pair if you pull them at a local pick-a-part. If you don’t have a local source for these knuckles, then visit the Moparts for sale section, or try Ebay. Installation of the knuckles should follow standard service manual procedure. If your car hasn’t had any front end work done in a while then you might take this opportunity to replace the ball joints, bushings and tie rod ends. Front suspension and brake work requires critical assembly work. Send the buddies with the pizza and beer home so you can share some quality time with your torque wrench!



Make sure you get the correct knuckles! The ones needed for this early B body swap have the casting numbers 3402626 and 3402627 on the upright. In the Mopar world, even numbers go on the right or passenger side, while odd numbers go on the left, or driver’s side. The later style casting shown on the right came on 1973 or later B-body cars as well as the FMJ body cars. The taller knuckles can also be used for this brake swap, but it is best to pair the tall knuckles with upper control arms which are designed for the extra height.  Call the guys at Firm Feel for the correct upper control arms to do the tall knuckle swap.

Here is the knuckle installed on the car. We have also installed the dust shield and the big 12 inch caliper adapter. The caliper adapter pictured here is the slider version. A pin type version of the caliper adapter is also available but seems to be harder to find. Either will work, just make sure your caliper style matches the adapter style. Most likely donor vehicle for the correct caliper adapters will be a 1976 or later B-body Mopar. Look for a Cordoba, Fury, Charger SE or similar car at the yard. Caliper adapters for the smaller 11 inch brakes look very similar but are too small to work with the big rotors. Make sure you get the right parts! We cheated by buying a set of adapters from a local source that had been re-machined and then nickel plated. New dust shields are still available from Dodge dealer under part number 3880518 and 3880519.

Once we had the knuckles and caliper adapters in hand, we visited the local auto parts store for the remainder of the items needed. Rotors are the 12 inch (actually 11.75 measured) ones listed for a 1978 Cordoba. Bearings, seals, dust cap, etc are for the same application, as are the calipers. When mounting these calipers onto an early B-body, the correct brake hose to use will be the one listed for a 1975 Duster. 


Just about finished. Note that the caliper hangs in front of the spindle, with the hose crossing under the upper ball joint and then hooking up to the hard line at the frame. This configuration allows you to use all factory parts. There were not any anti-sway bar interference problems with this installation since the early B-body cars had the bars attached to the brake strut. Check out the reference books for your specific year since some years will have a problem in this area.


Here is a slight twist on things. Lightweight Wilwood calipers mounted onto the the post-1973 knuckles and factory rotors. Mancini Racing sells the necessary pair of mounting brackets. Call 1-800-843-2821 if your Mopar needs some updating.

Another shot of the Wilwood setup, this time from the rear. These Wilwood calipers are not designed for full time street duty since they lack dust boots on the pistons, but they might be just the thing for a g-machine. They are close to 10 pounds lighter per wheel over the factory setup, and they clear the factory anti-sway bar mounts.

Here is a kit which is currently under development by Brembo. This kit mounts a Brembo four piston caliper onto the same A-body knuckle and uses the factory Cordoba rotor. Brembo hasn’t yet decided to market this kit so if you want brakes like this for your musclecar, contact them and let them know.

AR Engineering in Portland, OR is doing some serious Mopar brake development. Here is a shot showing a Brembo caliper mounted onto a 13 inch Mustang Cobra rotor. This whole assembly is mounted underneath an early B-body Mopar which is being built for serious g-machine duty.

With the big 12 inch rotors up front you’ll find that you do not need power brakes at all. The slickest setup is to bolt in the late model aluminum master cylinder using a 4 bolt to 2 bolt adapter bracket. An adjustable proportioning valve plumbed into the rear brake line finishes off the installation. A factory proportioning valve could also be used if you located one from a vehicle similar to yours. We used the adapter, as well as this slick looking master cylinder heat shield on our conversion. These items came from the parts department at Hershberger Motors.




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