Disc Brake Swap Recipe

[Dano 1]

It seems like almost every day there's a new disc brake swap thread started with questions about oem or aftermarket kits/parts. I just did this swap myself using all OEM parts pieced together from a bunch of different models per some of the articles you'll find online. I figured it'd be worth sharing the parts list if anyone wants to duplicate this setup and is willing to cross shop/order individual parts.



A few notes:
Spindles/knuckles: Either the FMJBR body or A body will fit, however, the A body units have the 'correct' geometry as they are exact duplicates of the b-body unit, just with the provision for caliper brackets. The FMJBR body knuckles are slightly taller and will fit but will also tweak the suspension geometry slightly. It's my opinion that the change is so mild you'll never notice any detrimental effects and may actually improve the camber curve but you'll find conflicting opinions. These can be sourced from the junkyard or head over to Dr. Diff for brand new repop units.

Caliper brackets: 76-78 Cordobas are the 'unicorn' donor as they have the caliper brackets to run the larger 11-3/4" rotors. Alternatively, Dr. Diff has repop units for either 11" or 11-3/4".

Discs: I went with 11" discs to be able to run 14" wheels so the part number listed in the table is for 11" units. If you go with 11-3/4" just lookup a 76-78 Cordoba and that will get you the correct 11-3/4" rotors. The calipers & pads are the same so it is just a rotor change.

Booster: My car was a power drum car so my pedal linkage worked just fine with the power disc booster. If you are going from manual drums you may need to purchase the correct linkage between the pedal and booster. Pirate Jack has all of these parts and a few different kits available to purchase everything together. This booster did require a slight firewall modification to get the snout of the booster to fit through the firewall, not the end of the world and completely hidden after the booster is installed.

I'm not going to claim this is the only combination of parts that will work but I just did the swap with these exact parts and everything bolted together just fine. All of the wear parts (rotors/pads etc.) are OEM replacement and are available at any major auto parts store for future replacement or repairs on the road which was the main reason I went this direction. Hopefully this info is useful and provides some guidance to anyone looking to make the jump to discs.

[70 sublime]

What do you figure it cost you to do it this way vs just getting a complete set up kit ?

[Nacho-RT74]

Rockauto offers drilled and slotted rotors too. I got them Centric, but it seems they are not available anymore but on a brand called Powerstop I think, a but more expensive than Centrics when were available from them. Accomplished with Raybestos metallic rear shoes and front ceramic pads. Sure my car was originally front disc, but pin kind caliper. I get onto this just in case you wanna know there are parts more than purelly stock as a stock replacement on the "performance" world as a tiny upgrade.

Otherwise, more info here

https://www.allpar.com/history/mopar/brakes/disc-main.html

Doctordiff ( same as other sellers ) offers the full OEM setup as a kit on $450 ( with stock rotors ) or so. What would make a cheaper option? if you get parts from local JYs such as spindles, calipers ( if just needing service ) and brackets.

[Dano 1]

What do you figure it cost you to do it this way vs just getting a complete set up kit ?

For all of the listed parts, except the spindles/caliper brackets, it came out to just under $600. I horsetraded for the spindles/brackets so those were 'free' for me but the Dr. Diff repro's are $150 for the spindles and another $50-$90 for brackets depending on 11" vs 11-3/4". Also Bear in mind I went with EBC pads which were $100+ by themselves so if you went with a cheaper pad you could save some coin.

I don't know that you'll save a drastic amount of money building your own kit but I like to choose exactly what parts I'm buying vs. just buying a kit with unknown source parts. The $450 Dr. Diff kit also does not include a power booster so if you want to go power you're going to be spending another $200+ for a booster.

[chargered]

Thanks for posting this.  Really good information for someone like me who is trying to do something similar.  I'm going to go with the Dr. Diff 11.75 rotors and caliper brackets.  Wondering if this Caliper from POL would work okay with this set up?  I was looking at these because I can get them in a red color.

https://www.performanceonline.com/mopar-disc-brake-caliper-1973-76-a-body-replacement/

[Dano 1]

I believe those will work just fine but I have not personally used them or had them in my hands.

Glad to help with my parts list, we're all here to learn and help each other out, at least that's how i see it. 

[chargered]

I ended up buying the newer steering knuckles/spindles and the 11.75 inch rotors from Dr. Diff.  My only problem is I have the 1970 pin style calipers so I need the larger caliper mounting bracket for the 11.75 inch rotors.  Does anyone know where I can get the larger caliper mounting brackets for pin style calipers?  Do I have to search the junk yards?