caliper retrofit for 69-73 spindles?

fury fan

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With 69-73 sliding pin calipers no longer available at the parts store, has anyone found an alternative?
A bolt-on that doesn't require a machine shop or some other expensive obstacle?
Or that maybe takes a simple flat adapter plate that a guy could make at home, or get lasered out from an internet fab shop?
Oh - and fits behind our 15" wheels, too.

Yes, the obvious answer is to get some caliper cores and get them rebuilt (and I have 4 cores here for that) but I want to evaluate other options - it will help all of us in the future if an alternative is found.
And if that potential solution had a larger brake pad, then braking would be improved also. Most modern multi-piston calipers would likely have larger pads.

One of the hurdles is that the caliper must fit over our 1.25" thick rotor - it seems the thickest of modern rotors are 1.18" thick (ignoring exotic/expensive cars), with many being around 1".
The 1" thickness of B-body parts precludes using any of those parts. (bearing differences prevent swapping to B-body rotors)
I have a dual-piston Crown Vic caliper (1.18" rotor) and it does seem to fit over the 1.25" thickness, but IIRC it has no chance of fitting in the 15" rim.

Perhaps one of those GM calipers that all the drum-brake conversion kits seem to use (the kits with flat-plate adapter brackets) would have potential - but I don't have any of those calipers laying around.
I've also noticed that most new calipers have brackets that are threaded, the bolts slide thru the spindle; the C-body stuff is the opposite. Drilling out a modern caliper bracket might afford some flexibility.

Some folks that made good comments in some older discussions I've read today (not meant to be an exhaustive list) that might want to be aware/contribute:
@Boydsdodge @70bigblockdodge @commando1 @Ross Wooldridge

@saforwardlook - IIRC sometime in the past you mentioned having contact with Centric, of maybe the plant was nearby?
If they have a catalog with some dimensions that would help. Rock Auto used to have Centric sketches with measurements on their rotors, but that seems to have gone away.



This page shows some measurements between E-body, C-body and 74-78 Formals, and the bolt spacing differs - so a Formal bracket/caliper is a no-go for a straight swap.
Using C-Body spindles on an E-Body ( and A-Body LCA's & Viper calipers)

Here's a similar thread, which concluded the Formal parts were a no-go.
Formal caliper brackets on 73 spindles....
1689261293739.png
1689261303377.png
1689261350270.png
 
Apparently Centric was "bought out" by another company a few years ago now and when I tried to contact them, it took a while to get through to a representative. When I asked him about availability of rebuilt calipers for our cars, that representative just told me they weren't going to supply those anymore. He never gave a reason or anything else. He really didn't care.

Before they were bought out, whenever I called them I always got a really good rep who really wanted to please whereas the new company rep was very hard to get to talk with and had an attitude of "couldn't care less". So I left it there and just take my calipers that need more than a simple rebuild to a brake shop near me that is probably the best one still left in existence called "Karps Brake Service". He can rebuild just about any brake booster of the past and he puts stainless sleeves in the calipers he rebuilds so issues should not be present for a very long time.

What is interesting is the original Centric was definitely a Chinese company and I spoke with the Chinese owner once and it was clear they wanted to be the best in the business and they were definitely successful. They even had a white guy answering the phones and he was the most knowledgeable, very helpful guy regarding brakes that you could possibly talk to.

The folks that bought out the well run Chinese company were white boys and their attitudes are disappointing.

As I look at all the Chinese EVs coming our way that are apparently well designed, I wonder what the future will bring to this country unless we develop a more competitive attitude toward business and also make higher education less expensive. From what I am observing, we are losing ground in the world market of automobiles with Musk being one lone exception..................
 
I believe B body calipers will work if they had 1/4 inch milled off of the surface opposite the piston
 
I am not so sure about that - from reports I've seen, they are a tad narrower than C body calipers, and when loaded up with pads, don't go over the rotor.
 
I believe B body calipers will work if they had 1/4 inch milled off of the surface opposite the piston

I am not so sure about that - from reports I've seen, they are a tad narrower than C body calipers, and when loaded up with pads, don't go over the rotor.
This came to my mind too.

The thing to do is compare the B to the C body caliper. It seems to me that someone had this issue and had a pic showing the difference. I have a loose C body caliper (no, it's not for sale) that I can measure etc.
 
Before we start milling on a B-body caliper we'd need to know if it would fit in a C-body bracket. Because the B-body bracket doesn't fit the C-spindle.
I would not be comfortable removing 1/4" of material from something that is smaller to begin with, and it's more of a machining setup than I can undertake anyway.

If someone made a custom bracket to use the 74-78 floating caliper, which has the hole locations to match a C-spindle, that would be a good solution.
Or - perhaps a flat-plate bracket is the best route.
1 design for drum spindles, 2nd one for disc spindles.
Just need to know what caliper(s) would be a good choice.
Now that both types of C-body rotors are available again, there's no need for bearing spacers or other tomfoolery.
 
They even had a white guy answering the phones and he was the most knowledgeable, very helpful guy regarding brakes that you could possibly talk to.

The folks that bought out the well run Chinese company were white boys and their attitudes are disappointing.

That demonstrates to the woke world that all white guys aren't the same!
Joking aside, thanks for the update on Centric. Sale-of-the-business explains the difference you experienced.
 
At the risk of sounding ignorant, but how hard would it be to retrofit the 74-78 formal  spindle?
 
I did some searching and found this: Calipers

While I would want to have these in my hands to really measure, it looks to me like it's the same overall width with a different inside width. Judging from these pics, there's enough material to cut 1/4" off with no problem. It looks like they are the same basic casting.

1689370596384.png
 
I think that photo is misleading in its perspective... and would respectfully siggest the B body casting is narrower.
I dunno...

As i said, I'd have to have one in each hand to really tell, but I think it's worth looking at. Another pic from that thread.

1689372021784.png
 
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