Disc Brake Conversion

Guys,
Can I assume from what I'm reading here, that I can use the 4 piston OEM style K/H brakes on the 1971 Maverick I'm getting that has 5 lug drum brakes? It sounds like the stuff will bolt correctly to the Maverick spindles?
TIA,
Gene

I'm not sure what the drum spindle on a 71 Maverick looks like. You will need to check the spindle and see if the patern matches the patern on Mustang drum spindles. If so, you should be able to use the factory adaptor brackets to bolt up the KH calipers.
 
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I'm not sure what the drum spindle on a 71 Maverick looks like. You will need to check the spindle and see if the patern matches the patern on Mustang drum spindles. If so, you should be able to use the factory adaptor brackets to bolt up the KH calipers.

The spindle on the left is from a '73 Maverick 5-lug drum brake car.
http://img249.imageshack.us/img249/8153/73maverickspindlesultra.jpg

It is the same spindle that would have come on the '70-up 5-lug drum brake Mavericks/'71-up 5-lug drum brake Comets. This drum spindle is also the same as what would have come on the '70-'73 Mustang/Cougars with 5-lug drums.

The Maverick drum brake spindle has the same 4-bolt hole flange pattern as the '65-'73 Mustang drum brake spindles.

In '74, Mavericks/Comets were optionally available with single-piston, floating caliper disc brakes. In '76 & '77, these disc brakes were standard equipment on the Mavericks/Comets. The single-piston, floating caliper front discs on the Mavericks/Comets are the very same discs that later came as standard equipment on the Granadas/Monarchs from '75-'80 that we commonly refer to as "Granada discs".
 
Guys,
Can I assume from what I'm reading here, that I can use the 4 piston OEM style K/H brakes on the 1971 Maverick I'm getting that has 5 lug drum brakes? It sounds like the stuff will bolt correctly to the Maverick spindles?
TIA,
Gene

Sure, get a pair of Raybestos 6004 Rotors, Change the races/bearing to the A 12-A 13. Install all this, the 4 piston setup, on the big bearing spindles (70 up Drum Brake) then you have the "Cobra Brakes".

We do this on a regular basis for folks.

Dan @ Chockostang
 
Sure, get a pair of Raybestos 6004 Rotors, Change the races/bearing to the A 12-A 13. Install all this, the 4 piston setup, on the big bearing spindles (70 up Drum Brake) then you have the "Cobra Brakes".

We do this on a regular basis for folks.

Dan @ Chockostang

I remember reading a post where [one of many times] you've publically blasted Dennis, of CSRP, for producing a "Granada" based conversion for sale to Mustang owners because more-or-less in a summary of your words, "they are not original" and "not period-correct for any vintage Mustang", and "it would have great potential to confuse a potential buyer of the vehicle in the future in not knowing what replacement brake parts to get for it"...and blah blah blah.

Now, in your reply to this person's question, you are advocating putting the 4-piston K/H brakes on a '71 Maverick, for which it was never original to. (???) --this wreaks of immense hypocrisy and is at complete odds, at least by your reasoning and what you've repeatedly said in the past, with regards to Mustangs and using "incorrect" "Granada" brakes on them.

The 4-piston K/H brakes had been out of production for 7 years by the time the factory single-piston, floating caliper brake system [the "Granada" brake sytem] was being put on the Mavericks/Comets from 1974-1977. The K/H 4-piston brakes were definitely "not stock" nor were they even "period-correct" for the Mavericks at all, but the "Granada" style brakes were factory-installed on the Mavericks/Comets.

As far as this particular individual is concerned, maybe he doesn't care if the brakes are "period-correct" for his vehicle. It's certainly his perogative what brake parts he decides to put on his vehicle but, this is not the basis of the point you have argued when it comes to "correct" brakes for vintage Mustangs. You can't have it both ways by your own statements and reasoning in what you've professed, previously on the subject. -unless in reality your true premiss isn't so much about what is "right", but instead, is really about the potential opportunity of selling what you offer to someone, whether the parts you sell are "right" or "wrong" for the application, which would seem to be ok if you do this but not ok if anyone else did the same type of thing. --this would be the part where that hypocrisy thing really starts to kick into overdrive.

It would seem the common motive here, in your recommendations for what type of brake system a person should use, always [conveniently] falls back on the particular product that you sell, and never is your advise given towards a brake system you do not offer. --even if that other brake system really is the "correct" one to use for their application in question.

You've repeatedly blasted one guy for offering "incorrect" "Granada" brakes for early Mustang usage, but here, you advocate using the incorrect early-Mustang K/H-style brakes on a Maverick. --Hmmmm. Right application or wrong application, I guess we shouldn't cloud the issue with facts when the motive is to just simply sell something to someone. :bs:
 
Please Allow Me To Interject A Bit Of Levity Here,
C'mon boys, let's play nice. There are enough turds in the sandbox for everybody to have at least one or two. When I first posted a question about a Maverick, I didn't expect anyone to give a rat's toockus about whether it was original, period correct or any of that, after all, this is a Mustang site, I'm just thankful for informed and thoughtful replies. I, for one, applaud all of you folks who spend your time, effort, $$$ and skills coming up with new ways to skin a cat and make our cars safer and more personalized with choices/options for different levels/types of performance. When I first became interested in Hot-Rodding, the pastime wasn't about laying down a pile of $$$$ to get "just what you wanted" or a pile of chrome goodies, but more of going out to a buddy's uncle's/grandfather's junkpile to figure out what you could make work/fit and giving him a case of beer or such to let you take what you thought you could use/modify for your purposes. For what it's worth, my question was brought up from my own thoughts of using my Maverick spindles to allow the use of cool 4 piston calipers on my 68 Mustang "Hot Rod" while taking my lighter duty 68 spindles and single piston calipers to use on my wife's soon to be daily driver, 71 Maverick, 250-6 cylinder with an AOD. Interchange and swapping is what it's all about and a day will come when the only way we'll be able to continue to enjoy our old rides is to be inventive, imaginative but above all, SAFE. We're all supposed to friends here, and should treat each other as such without trying to piddle on each others' parades. Opinions are wonderful, but remember, like other human parts, "everybody's got one"!:lol:
Love Ya, (in the worst way):uzi:
Gene
 
Please Allow Me To Interject A Bit Of Levity Here,
C'mon boys, let's play nice. There are enough turds in the sandbox for everybody to have at least one or two. When I first posted a question about a Maverick, I didn't expect anyone to give a rat's toockus about whether it was original, period correct or any of that, after all, this is a Mustang site, I'm just thankful for informed and thoughtful replies. I, for one, applaud all of you folks who spend your time, effort, $$$ and skills coming up with new ways to skin a cat and make our cars safer and more personalized with choices/options for different levels/types of performance. When I first became interested in Hot-Rodding, the pastime wasn't about laying down a pile of $$$$ to get "just what you wanted" or a pile of chrome goodies, but more of going out to a buddy's uncle's/grandfather's junkpile to figure out what you could make work/fit and giving him a case of beer or such to let you take what you thought you could use/modify for your purposes. For what it's worth, my question was brought up from my own thoughts of using my Maverick spindles to allow the use of cool 4 piston calipers on my 68 Mustang "Hot Rod" while taking my lighter duty 68 spindles and single piston calipers to use on my wife's soon to be daily driver, 71 Maverick, 250-6 cylinder with an AOD. Interchange and swapping is what it's all about and a day will come when the only way we'll be able to continue to enjoy our old rides is to be inventive, imaginative but above all, SAFE. We're all supposed to friends here, and should treat each other as such without trying to piddle on each others' parades. Opinions are wonderful, but remember, like other human parts, "everybody's got one"!:lol:
Love Ya, (in the worst way):uzi:
Gene

It would be great if everyone would "play nice", as you say, but Dan [Chockostang] chooses not to work well with others --and by others, meaning he doesn't like any form of competition that might possibly take a sale away from him. He purposely gives convoluted information out to make his competitors look bad in order to try and make himself look good. You don't have to take my word for it. You can search on this forum, or any other related forum, where the subject is disc brake swaps and what his comments have been.

Truth-be-told, I couldn't care less about "originality" when it comes to older Mustangs. I have a lot of modifications that have been done, or are in the works, on my own '68 Mustang that are far from "stock" or "period-correct".

I only seized upon this opportunity when Dan snared himself, by his own words, and what he's been preaching against when it comes to putting "wrong" parts on particular applications. It seems to only be "wrong" if it's done with his competitior's offerings, but not wrong in cases if it is done with what Chocko himself sells.

I've been a member on this site [and other related sites] for a very long time now. I don't think post counts are an accurate number representing what a person knows, but they are an accurate indicator of how many times a person has made a post there. My post count here is over 1,000. In some of those posts, I have said something in promotion of what I sell. In some of them, it was to promote what someone else sells. Some were on general topics completely unrelated to Mustangs at all. Often times, my reply was to give information not even related to brakes and I knew ahead of time my time and effort replying would have no potential of earning me a single dime for my help. Check Dan's post history and see how many times he has simply offered useful information to help someone on something that wasn't even related to brake systems vs. how many times it had to do with the possiblity of him getting a sale off someone. [That shouldn't take too long].

Dan has also made posts against me and several others who have designed/produced their own adaptive means ["homemade" parts, as Dan put it, in an effort to demean the product] to adapt later model disc brake components onto the older Mustangs & related Fords. Disregard that these are [at least in my case] Ford, time tested and proven components and have proven to be both highly effective and highly reliable in operation in their adaptive existences. Dan claims people like me won't be here 30 years from now and where would the customer get replacement parts from? In my case, the reality is the brake parts are Ford [Lincoln Mk VII, SN95 Mustang V6/GT & SN95 Cobra rear disc brake parts]. The main thing I offer is the adaptive means to put the Ford brake parts on the end of the rear end housing --the brackets. The brackets I produce are a non-wear item so they aren't going to wear out, whether I'm still around or not. The brake parts themselves are Ford. Pretty good chance they will still be available through parts stores or from the internet.

Dan claims the K/H reproductions of the early Mustang front discs have been around for 30 or more years and will be around for 30 more, to encourage people to stay away from what anyone else offers. He does this to create the illusion and doubt in people's mind that only what he has will be around and what everyone else has won't be. If you can still get a disc brake rotor [or any other related part] for a 45-year old Mustang today, there's a real good chance someone will be able to get a 13" SN95 Cobra rotor [for example] 30-years from now, especially since the SN95 Mustangs are much more popular than the vintage Mustangs. However, I don't think Dan is a wizard with a crystal-ball. We might have a good idea what will happen tomorrow but since tomorrow hasn't happened yet, we can't say with 100% certainty what will or will not be. --Let alone, trying to predict what will be in 30-years from now. GM was a giant that almost fell --had it not been rescued at the tax-payers expense, it would be gone now. IF SSBC falls on economic troubles bad enough to force it out of business, it isn't going to get the same taxpayer dollars [as GM], to save it. --There goes their production of replacement parts and the collapse of its network of dealers for them.

Here's my take on the Chocko situation; Up until about 10 years ago, early Mustang & related Ford owners had basically two options if they wanted to upgrade their drums to discs: expensive arftermarket or wrecking yard solutions. There wasn't really an affordable in-between solution. There were people like Wilwood, Baer, or SSBC [and their network of associated dealers, like Dan] offering setups that were custom brake systems, or replicas of older Ford brakes sytems. The price tag for these systems are often out of reach of many "average" Mustangers on a tight budget.

The second option Mustang owners had, up until about 10 years ago, was to find disc brake components from wrecking yard donors. Dan was among an elite few dealers up to this point, who offered a new front disc brake conversion for Mustangers and related Ford owners. Up until a decade ago, he was pretty much on top of the heap -so-to-speak, but then people like me and my company, Ultrastang.com, and Steve Wilkes of MustangSteve.com, John Dinkle of Opentracker.com, Shaun Burgess of StreetorTrack.com, and Dennis Ginsberg of DiscBrakeSwap.com, as well as a number of others, began to emerge and offer adaptive disc brake solutions, or quality reproductions of Ford designed disc brake systems, that are generally much less than what it cost to purchase the SSBC brake system. This is when the ground began to erode under Dan's feet and he began to lose sales to other people's offerings.

No longer being at the top-of-the heap, Dan's tactics had to turn to saying things like;"homemade", for instance, in order to make it sound like an inferior product to try and sway potential customers away from the 'new guys on the block' and back towards what he was selling. Or, if it was someone else's reproduction of actual Ford brake setups [Granada], he was saying that they were "wrong" and not "period-correct" and so forth to try and keep the sale of them from happening.

He touts the K/H discs as being "bigger" than the Granada. While they are, I also refuted the fact that they are only marginally bigger. His list of half-truths and misinformation goes on and on --which again, you don't have to take my word for it, you can search the archived messages at this and various related sites to see the words directly from 'the man himself'. As I've said before, there's room in this hobby for all of us that offer some type of brake system for sale. Chockostang tries to present himself as a good ol' boy just looking out for the interest of the [potential] customer. The only thing he is looking out for is relieving you of the dollars in your pocketbook to place them in his own, whether this means giving someone factual information, half truth information, flat out lying or slamming someone else's product to make his own look better is of no concern to him.

And here again, in reality, I wasn't even advising you to buy from anyone here. My actual opinion would be for you to go to a wrecking yard and get the parts you need off a disc-equipped Maverick or off a '75-'80 Granada/Monarch, since they have the same disc brakes that were used on the Mavericks. I gave you the facts as to what brakes were a viable option for your Maverick. It also turns out that what I recommended is actually the "correct" style brakes for it. The choice remains yours in what type brakes you run, "correct" or "incorrect", and whether you buy them new from some brake supplier, or whether you circumvent all this by going to a wrecking yard and pulling what you need, yourself.
 
Y'know; I was going to post up the "popcorn" smiley near the bottom of the first page of this thread; but didn't think it would set the right "tone", so I didn't.

Now I'm going to do it :popcorn: Twice :popcorn:

Nice lively discussion without flames; just facts along with empirical evidence gathered right here in this Forum. :nice:

Publicly not taking sides here. One of the posters actually produces the kits that I'm going to want when I get my Cougar back on the road - and he knows it (if he checks his old PM's). Presently, my Cougar has the "Granada setup" - and it originally came as "standard equipment" from Ford (technically, Mercury) that way!

Sometimes, an owner/driver thinks that system still isn't enough on today's roads, with today's drivers....
 
Guys,
Can I assume from what I'm reading here, that I can use the 4 piston OEM style K/H brakes on the 1971 Maverick I'm getting that has 5 lug drum brakes? It sounds like the stuff will bolt correctly to the Maverick spindles?
TIA,
Gene

Gene,

You need a bit of advise on the conversion, call I'll direct you to the parts locally, or if needed, we'll sell them to you.

As you know, this conversion is not a item we sell on E Bay, or on our sight, but try to assist if we can to those in need.

Dan @ Chockostang
 
...Dan has also made posts against me and several others who have designed/produced their own adaptive means ["homemade" parts, as Dan put it, in an effort to demean the product] to adapt later model disc brake components onto the older Mustangs & related Fords. Disregard that these are [at least in my case] Ford, time tested and proven components and have proven to be both highly effective and highly reliable in operation in their adaptive existences.

If so, poor Dan would probably have an embolism if he saw our budget offering for small Fords. See that caliper? Celebrity :eek:


and the rotor hat? why it's Toyota! :eek: :eek: :eek:


Funny thing about the Toyota rotor - it's bolt pattern and pilot hole are exactly the same size as vintage Ford - so it fits a modified drum hub like it was factory-made, and the whole assy fits inside the stock drum wheel which to me is more important than whether Dearborn designed it or not...
 

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If so, poor Dan would probably have an embolism if he saw our budget offering for small Fords. See that caliper? Celebrity :eek:


and the rotor hat? why it's Toyota! :eek: :eek: :eek:


Funny thing about the Toyota rotor - it's bolt pattern and pilot hole are exactly the same size as vintage Ford - so it fits a modified drum hub like it was factory-made, and the whole assy fits inside the stock drum wheel which to me is more important than whether Dearborn designed it or not...

Dam, I now know why I had a bad Day Sunday, it was the Scarebird brakes.

A Embo---What I can't even comprehend what that might be--Hope not to bad???

Anyway you Folks at Scarebird have a wonderful Holiday, Great New year!!!!

Dan @ Chockostang
 
Just To Set My Record Straight,
In the year and more that I've been a member here, I've received courteous, friendly and informative/knowledgeable responses equally from chocostang, scarebird and ultrastang and would gladly have a beer and spirited discussion with any/all of them. My thanks go out to all who share their knowledge and experience.
My $.02,
Gene
 
Sure, get a pair of Raybestos 6004 Rotors, Change the races/bearing to the A 12-A 13. Install all this, the 4 piston setup, on the big bearing spindles (70 up Drum Brake) then you have the "Cobra Brakes".

We do this on a regular basis for folks.

Dan @ Chockostang

Let me clarify some misinformation that has been stated in the above comment, in reference to the "Cobra" name, with respect to the '60s-era Mustang disc brakes.

There has never been a disc brake system produced by Ford and installed on the '60s-era Mustangs that was referenced to as a "Cobra" setup, by Ford.

The simple act of installing a K/H rotor/4-piston caliper on a beefier designed early spindle doesn't make it a "Cobra" setup. It's just a K/H caliper and rotor on a stronger spindle.

The Cobra II's had Pinto brakes, so I won't even count them here.

Technically, and in the real world, the first instance of an actual Ford-produced disc brake system installed on a Mustang [that could be considered "Cobra" brake parts] came with the production of the 1993 Fox-bodied SVT Cobra Mustangs. These were 4-lug setups with discs on both front and rear of the vehicle.

--Even more technically so [in reference to the "Cobra" name] would be the brakes that were installed on the 1993 SVT Cobra R's [only 107 Cobra R's were produced. All were red in body color]. The Cobra R's were the very first Mustangs to receive the massive 5-lug 13" front rotors with the aluminum, twin-piston, PBR floating calipers. The rear brakes of the '93 Cobra R's had 11-5/8" ventillated discs with a single-piston Varga floating caliper. --These are the same brake components that carried over as the standard brake equipment for the 1994-2004 SN95-bodied SVT Cobra Mustangs.

For the '94-'04 Cobras, the word "COBRA" is actually written across the outboard face of the front calipers [visible through the spokes of the wheels]. All '94-03 Cobras have charcoal-colored calipers with the "COBRA" script on them. The 10th-anniversary SN95 Cobras [2004], had red calipers with the word "COBRA" on them as designed and produced from Ford under such designation.

'94-'03 Cobra calipers:
fmsm2320cw.jpg

10th anniversary [2004] Cobra calipers:
414asfe0p4lss500.jpg

'01 Bullitt Mustangs also had the same massive brake components as the '94-'04 Cobra Mustangs. However, the the only difference is the Bullitt calipers were red with a running horse insignia on the front calipers instead of the word "COBRA".

'01 Bullitt calipers [still, technically, "Cobra" brake components]
fmsm2320fw.jpg

'03/'04 Mach 1's also had the same massive brake components as used on the '94-'04 Cobras and '01 Bullitts. '03/'04 Mach 1 calipers were charcoal-colored and didn't have either a running horse or a logo on them. [they were plain] but still, technically, they are real "Cobra" brake components.

The '93 SVT Cobra/Cobra R, '94-'04 SVT Cobras, '01 Bullitts, '03/'04 Mach 1's actually had factory "Cobra Brakes", but no vintage era-Mustang ever had any brake components [beefy spindle or not] that was referenced to as a "Cobra" setup, by Ford.
 
I think he may have ment the Boss Mustang setup but they didn't use the standard 4 piston K/H caliper on the front. They used the larger 4 piston K/H caliper on the front, same as the 65 TBird. The smaller/early Mustang K/H caliper was used on the Boss for rear disc brakes, I don't know what rotor they used.
 
I think he may have ment the Boss Mustang setup but they didn't use the standard 4 piston K/H caliper on the front. They used the larger 4 piston K/H caliper on the front, same as the 65 TBird. The smaller/early Mustang K/H caliper was used on the Boss for rear disc brakes, I don't know what rotor they used.

"Continental" or "Galaxie" big brake upgrade would be more accurate of a description, but definitely not "Cobra".


'69/'70 T/A Boss 302s [the factory-prepped race cars for the Trans Am racing series] had the beefy 4-hole flange spindles with larger pins and the larger hole for the outer tie rods. These were heavy-duty drum-style spindles outfitted with the larger 4-piston calipers/rotors from the bigger '65-'69 Lincolns or Ford Galaxies of the era.

However, the street-production Bosses didn't run drum brake-style spindles. They had factory single-piston floating calipers and a [true] disc brake spindle --the ones that are the close cousin of the Granada spindles. The regular production Boss 302s also had drum brakes on their 9-inch rears, just like the other regular production Mustangs.


Stock 1969 [non-T/A] Boss 302 front brake/suspension photo:

dsc00203hz.jpg

Even with the big Lincoln/Galaxie upgrade, the rotors are still 1" smaller in diameter than the 13" SN95 [true] "Cobra" rotors. ;)
 
I didn't know they had different brake/spindle combos on the Boss vs Boss TA. Did the Boss 429 also have the standard brakes ?

Yes, the rotor is 1" smaller but it is a fixed 4 piston caliper with big pistons instead of a floating 2 piston caliper. If someone wants a more period correct piece that doesn't require larger rims it is a good option... except for the fact that the brackers on the market today are WAY over priced.
 
Let me clarify some misinformation that has been stated in the above comment, in reference to the "Cobra" name, with respect to the '60s-era Mustang disc brakes.

There has never been a disc brake system produced by Ford and installed on the '60s-era Mustangs that was referenced to as a "Cobra" setup, by Ford.

The simple act of installing a K/H rotor/4-piston caliper on a beefier designed early spindle doesn't make it a "Cobra" setup. It's just a K/H caliper and rotor on a stronger spindle.



Absolutely a fact here!

The earlier statement was to expose the fact that these are mearly common 4 piston disc brakes, on the 70 Drum brake spindle, that have been around for years.

There are those that call them "Cobra Brakes" and some seem to believe they are a exotic style of Disc Brakes.

Dan @ Chockostang
 
I didn't know they had different brake/spindle combos on the Boss vs Boss TA. Did the Boss 429 also have the standard brakes ?

Yes, the rotor is 1" smaller but it is a fixed 4 piston caliper with big pistons instead of a floating 2 piston caliper. If someone wants a more period correct piece that doesn't require larger rims it is a good option... except for the fact that the brackets on the market today are WAY over priced.

The Boss 429s used the same brake rotors as the other '68-'73 Mustangs with disc brakes, but the hubs were different to fit the wider Kar Kraft spindles that were unique to the Boss 429s [early Mustang discs had two-piece rotors/hubs]. The production spindle pin for the Mustang is around 4.5" wide. The KK Boss 429 spindle was 5".

Boss 429s also used production Mustang drums on the 9-inch rears.

Dan had made reference to the Raybestos 6004 rotor [installed on an early, heavier, '70 Mustang spindle]. That is the 11-19/64" '65-'67 rotor for the associated [smaller] '65-'67 Mustang 4-piston K/H brake caliper. If he had been referencing the bigger Lincoln/Galaxie 11.72" rotor and the associated larger 4-piston K/H caliper, then the rotor number would have been the 6008 part number. The Raybestos 6008 Lincoln/Galaxie rotor is 11-23/32" in diameter, or two 'ticks' under 11-3/4". --So, to correct my earlier statement that the Lincoln/Galaxie rotor was 1" smaller than the SN95 Cobra 13" rotor isn't correct. It's actually more than 1-1/4" smaller than the Cobra rotor. [I thought the 6008 rotor was a full-12", but it isn't]. --Also, putting a '70 spindle [actually, any '67-'73 Mustang spindle] on a '65/'66 Mustang will give you the same incorrect steering geometry as using wrecking yard Granada spindles on a '65/'66 Mustang.

Stock 14" wheels will fit over the standard '65-'67 Mustang K/H disc brakes, but I'm fairly certain the stock Mustang 14" wheels will not fit over the larger Lincoln/Galaxie K/H brake version. If this is correct, it would require 15" diameter wheels, minimum, for the bigger Lincoln/Galaxie setup.

I'm not sure what the actual reasoning behind going from fixed calipers to floating calipers [really] was (?). The 'popular belief' seems to be it was because of a production cost-savings thing [cheaper to produce].

I might would believe this was totally true on your average production Ford Taurus, Chevy or Chrysler 'Whatever', but if a "fixed" caliper is "better" than a "floating" caliper, why did a high-end [expensive] car like a '94-'04 Cobra come with floating PBR calipers if "fixed" was really better? --these weren't ["cheaper"] production brakes taken out of the common parts bins that were going on the other commonly-produced Mustangs/Fords. This was a more expensive, secialty brake setup.

Maybe you know this and maybe you don't, but the C5 Corvettes, --a very high-end, expensive car --even more so than the Cobra Mustangs came with a twin-piston, floating PBR caliper & 13" Brembo rotor that is very close to the same design as the PBR floating twin-piston caliper and 13" Brembo rotor that came on the SVT Cobras.

http://image.gmhightechperformance.com/f/8749118+w750+st0/0602gm_brakes_z.jpg

The Corvette is geared toward a market that is generally much more financially secure and can more afford a high-cost car like the Corvette. If the fixed caliper really is so much better, Chevrolet could have easily installed the more "expensive" fixed caliper design and simply passed that cost onto the consumer, in the price of the car.

A possible reason domestic auto manufacturers got away from fixed calipers, since the mid-'60s, may be because as long as the rotor on a fixed caliper setup has a tight axial and radial runout, the caliper is happy. As the rotor gets hot though, it begins to expand. As long as the rotor remains "true", things are fine. However, if the rotor does not expand evenly, or if it gets too hot, it will start to distort. As the distortion tries to pass through a fixed caliper, the caliper has nowhere to go. This produces the phenomenon known as "knock-back" where the rotor slams the pistons of the fixed caliper back up into the piston bores of the caliper, since they are the only things that can give.

A floating caliper does not have this problem. Since it "floats", it is able to follow along with any in-or-out movements of the rotor's friction surfaces and is still able to grab the rotor to reduce the vehicle's speed.

Like I said, I don't know what the definitive reason is behind why domestic auto manufacturers switched over to floating caliper systems, but these are just some things to consider as to why they did.
 
A fixed caliper is superior in performance to and equivalent floating caliper, if only by a little bit. Fixed calipers are more expensive then the floating calipers, they require more maint. and over time can require recentering on the rotor. I imagine all of these together make a good argument for most manufacturers to use a floating design. You will notice on the true high end cars that they don't use floating calipers, they don't need to save cost on production and they expect people to be ok with the added maint. cost down the line.