71 0r 72 Charger front disc spindles on a 70 Challenger

[GoMangoBoys]

We want to convert our 70 Challenger from front drum to front disc.  I have a chance to pick up spindles, caliper brackets and dust shields from a 71 or 72 Charger for practically nothing.  Are these the same as what came on the Challenger?  If they are a little different, will they work correctly?
Thanks

[Chryco Psycho]

They will work perfectly
Scarebird does a disc conversion using the drum spindles & common parts also as another option

[BFM_Cuda]

71 or 72 Charger will be a direct bolt on for that year Challenger. I would use RockAuto to order all the parts.

73-up disc spindle has a larger inner wheel bearing so you need later-year bearings, seals, and rotors.


Large spindle conversion article:
https://www.allpar.com/history/mopar/brakes/disc-main.html

[kawahonda]

This is on my list of things to do eventually. Probably will post a second thread asking the same question.

Does a front-disc swap harm value of a challenger?

[Chryco Psycho]

not in my opinion , these cars should have had brakes that matched the performance of the engines , sadly a high percentage only had drum front brakes .
Purists would still want the drums but probably rarely drive them & never hard .

[kawahonda]

Is there a perceivable difference between drum brakes and HD drum brakes?

I've noticed that my HD drum brakes stop rather well (340). I'm not of course "interstating it" or putting myself in positions where "fade" could become any issue.

[71383bee]

not in my opinion , these cars should have had brakes that matched the performance of the engines , sadly a high percentage only had drum front brakes .
Purists would still want the drums but probably rarely drive them & never hard .

100% agree! 

Putting on a factory disc setup is the way to go if you have the ability to do so.  Its worth a few points off if your being judged and the judges don't have to drive it anywhere.  I've sailed through intersections with only a prayer stopping me on one of my all drum cars!  Why they didn't just mandate this earlier confounds me.  Your at the dealer ordering up your big block challenger and you go nah the original brakes are fine...  I get inflation and all but wasn't it like a 20-30 dollar option?

[anlauto]

Keep in mind discs use a different master cylinder and distribution block than drum brakes 

[GoMangoBoys]

I was assuming that I had to change the master cylinder and the proportioning valve.  I did this once on a 67 Pontiac Lemans.  I used all the hardware froma 67 Chevelle / GTO.  It all dropped right in and was factory correct. 
The difference in stopping ability was immense which is why we are going to the effort to do this upgrade on my son's Challenger.

Additional questions related to this upgrade.

1. If I am not mistaken, the original setup was a 2 piece hub/rotor.  It looks like replacement rotors are available as well as replacements that are 1 piece hub/rotor.  If I want to stick with the 2 piece set up, are replacement hubs available that don't have the integral rotor?

2. Is the master cylinder for disc the same size as the one for drum?  Any issues with changing from the drum to disc master cylinder?

[anlauto]

If you run the newer 1973 spindles with the larger rear bearing the price of replacement rotors drops from $400/each to about $40 each....check Rockauto to see what I mean. I don't think you can buy a rotor to replace just the rotor on the two piece design, but you can buy a one piece replacement rotor.
The master cylinders will be a direct swap.

[Chryco Psycho]

You can & should go to a disc brake master just for the extra fluid capacity for the disc brakes   , the square front ones are easy to get still , if you swap the rear wheel cylinders to truck ones you can get away without a proportioning valve , @Brads70 can help with part #s .
The new master will just bolt onto the booster assuming you have power brakes you will have to adjust the pushrod length to make sure the master fully retracts , too long &  or too short so there is no excessive play .
It is not worth trying to stay with 2 piece rotors, the 1 piece are more available & reasonably priced 

[Dakota]

If you look at the eBay store for the the author of the Allpar article that BFM_Cuda posted (Rick Ehrhenberg), he recommends suggesting that smaller diameter (vs. OE) rear brake cylinders be used if you're doing a front disc conversion AND you are using a stock (non-adjustable) proportioning valve.  This change is supposed to avoid premature rear brake lock up.   I hadn't heard about this concern previously.  The smaller brake cylinders are available through the link below:

https://www.ebay.com/itm/for-MOPAR-Disc-Drum-Brakes-Lockup-Proportioning-Fix-Plymouth-Dodge-A-B-E-Body/223861663094?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

[Brads70]

You can & should go to a disc brake master just for the extra fluid capacity for the disc brakes   , the square front ones are easy to get still , if you swap the rear wheel cylinders to truck ones you can get away without a proportioning valve , @Brads70 can help with part #s .
The new master will just bolt onto the booster assuming you have power brakes you will have to adjust the pushrod length to make sure the master fully retracts , too long &  or too short so there is no excessive play .
It is not worth trying to stay with 2 piece rotors, the 1 piece are more available & reasonably priced

https://forum.e-bodies.org/wheels-tires-brakes-suspension-and-steering/12/rear-drum-brakes-locking-up-before-fronts-try-truck-rear-wheel-cylinders/3018/msg43894#msg43894