Oddball car - swap to disc - ideas?

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Backtobasics

Backtobasics

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1976 Dodge Dart Lite. Car was supposed to be big bolt pattern disc, with 4 speed OD. Mine is very early 1975, and is small bolt pattern, and drums on all 4 corners.

I have searches ScareBird, they only service up to 1972.
Ebay listings show complete kits for 395.00 but all say that 75-76 use different upper arms.

It appears the asumption is that 73-76 will already have discs. It is my understanding that /6 cars in these years had drums. Besides a factory setup, does anyone have any ideas?
 
Since you should already have the large ball joint control arms just go with the A, F, M, J spindle swap. Cars like the 85 5th Avenue should be fairly common in the salvage yards....
 
mguner said:
Since you should already have the large ball joint control arms just go with the A, F, M, J spindle swap. Cars like the 85 5th Avenue should be fairly common in the salvage yards....
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How do I know I have the large ball joint.
If this is what I have, then all I need from the salvage yard, is the spindles, caliper brackets? What rotors do I use? I appreciate the help.
 
To get some facts straight, a-bodies built after December 31st 1975 all had disc brakes and big bolt pattern regardless of engine or options.
From the start of the 1973 model year, all V8 a-bodies had big bolt pattern and disc brakes.
From the start of the 1973 model year, all slant six a-bodies had big bolt pattern and disc brakes ONLY if they were ordered with power brakes.
All non power brake equipped slant six a-bodies from the 1973 model year had small bolt pattern 9'' drum brakes until January 1, 1976.
All a-bodies older than the 1973 model year had small bolt pattern brakes regardless of options. The only exception to this rule was the factory Super Stock Barracudas and Darts for 1968, which were all big bolt pattern with retrofitted b-body parts on them.
 
Dartnut said:
To get some facts straight, a-bodies built after December 31st 1975 all had disc brakes and big bolt pattern regardless of engine or options.
All non power brake equipped slant six a-bodies from the 1973 model year had small bolt pattern 9'' drum brakes until January 1, 1976.
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My Dart Lite has a build date of 11/75, and is non-power assist. It falls directly into this window. The ultimate goal is to get disc and big bolt pattern on the front, and then use a Scarebird kit on a cut down C-Body 8.75 for disc brakes on all 4 corners.
 
Just get the 73 through 76 A body discs brakes. Including upper control arms. Save old calipers, and master cylinder for cores. Get the proportioning valve and brake lines under the hood since the master has some unique brake lines fittings.
 
Backtobasics said:
My Dart Lite has a build date of 11/75, and is non-power assist. It falls directly into this window. The ultimate goal is to get disc and big bolt pattern on the front, and then use a Scarebird kit on a cut down C-Body 8.75 for disc brakes on all 4 corners.
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The c body shoes and drums that are on the 8 3/4 will out last the pads,rotors and calipers of a disc set up by a large margin. Just mentioning this as some may not realize this. They do weigh a bit more but it is in the rear so it is of no real consequence to performance on a street car where the car hasn't been extensively lightened as a drag car.
Most (not all)rear disc kits sold are light duty parts pirated from modern cheaply built cars and tend to wear or burn up at a quicker rate than the heavy duty drums you may already have.
My intention is not to get the fur flying over these points from the rear disc guys, just you could save a good bit of cash without any lack of performance if your axle still has the brakes on it it came with.
I mostly decided to type this out due to your username being back to basics, thought it may help.
 
The '75 will have large ball joint upper control arms even though it has SBP drums. All you need is the 73+ A or FMJ spindles, you don't need UCA's. To do the OE 73+ disk conversion all you will need is the 73+ spindles, caliper brackets, calipers, and rotors.

Also, 73+ cars with drums did not have 9" drums in the front. The last year for 9" front drums was 1972. '73+ drum cars came with 10" drums and large ball joint UCA's.
 
furyus2 said:
Just get the 73 through 76 A body discs brakes. Including upper control arms. Save old calipers, and master cylinder for cores. Get the proportioning valve and brake lines under the hood since the master has some unique brake lines fittings.
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I haven't been able to find this setup without effectively buying a whole parts car.

ssba said:
The c body shoes and drums that are on the 8 3/4 will out last the pads,rotors and calipers of a disc set up by a large margin. Just mentioning this as some may not realize this. They do weigh a bit more but it is in the rear so it is of no real consequence to performance on a street car where the car hasn't been extensively lightened as a drag car.
Most (not all)rear disc kits sold are light duty parts pirated from modern cheaply built cars and tend to wear or burn up at a quicker rate than the heavy duty drums you may already have.
My intention is not to get the fur flying over these points from the rear disc guys, just you could save a good bit of cash without any lack of performance if your axle still has the brakes on it it came with.
I mostly decided to type this out due to your username being back to basics, thought it may help.
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The C body axle I have is bare. It will need brakes, regardless. While it might not be necessary on a street car, I like the visual balance of discs on all 4 corners. If I am going to go downt the "fix it" road, then might as well make it look better.
The screen name is for me getting back to my Mopar roots. I still give props, you are attentive.

72bluNblu said:
The '75 will have large ball joint upper control arms even though it has SBP drums. All you need is the 73+ A or FMJ spindles, you don't need UCA's. To do the OE 73+ disk conversion all you will need is the 73+ spindles, caliper brackets, calipers, and rotors.

Also, 73+ cars with drums did not have 9" drums in the front. The last year for 9" front drums was 1972. '73+ drum cars came with 10" drums and large ball joint UCA's.
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I have seen FMJ in my local yards. If I grab the spindles, caliper brackets, then I should be able to buy quality rotors, bearings, and pads, hoses, then I should have front discs with 5x4.5 bolt pattern?
 
Backtobasics said:
I have seen FMJ in my local yards. If I grab the spindles, caliper brackets, then I should be able to buy quality rotors, bearings, and pads, hoses, then I should have front discs with 5x4.5 bolt pattern?
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Yup. And that's all I would get from the yard too, just the spindles and caliper brackets. Most yards charge about the same for a set of calipers as the core charge on a rebuilt set, so, you're better off just paying the core charge on the rebuilt calipers.

Here's a list of potential spindle donors. Nowadays the 5th ave's and the Diplomat's are usually the only sources that still end up in the yards, and even they get there less frequently than they used to.

These would have the 10.98" rotors

CHRYSLER CORDOBA 1975-1983
CHRYSLER FIFTH AVENUE 1983-1989
CHRYSLER IMPERIAL 1981-1983
CHRYSLER LEBARON 1977-1981
CHRYSLER NEW YORKER 1982
CHRYSLER TOWN & COUNTRY 1977-1981
DODGE ASPEN 1976-1980
DODGE CHALLENGER 1973-1974
DODGE CHARGER 1973-1976
DODGE CORONET 1973-1976
DODGE DART 1973-1976
DODGE DIPLOMAT 1977-1989
DODGE MIRADA 1980-1983
PLYMOUTH BARRACUDA 1973-1974
PLYMOUTH CUDA 1973-1974
PLYMOUTH DUSTER 1973-1976
PLYMOUTH FURY 1975-1976
PLYMOUTH GRAN FURY 1982-1989
PLYMOUTH ROADRUNNER 1973-1975
PLYMOUTH SATELLITE 1973-1974
PLYMOUTH SCAMP 1973-1976
PLYMOUTH VALIANT 1973-1976
PLYMOUTH VOLARE 1976-1980

These came with 11.75" rotors. Same spindles, different caliper brackets and rotors. Even better to find because you can run the larger 11.75" disks up front with the caliper brackets you'd get from these. Although, that means 15" rims minimum.

CHRYSLER CORDOBA (1976 - 1979)
CHRYSLER NEW YORKER (1979 - 1981)
CHRYSLER NEWPORT (1979 - 1981)
DODGE CHARGER (1976 - 1978)
DODGE CORONET (1975 - 1976)
DODGE MAGNUM 1979
DODGE MONACO (1977 - 1978)
DODGE ST. REGIS (1979 - 1981)
PLYMOUTH FURY (1976 - 1978)
PLYMOUTH FURY SALON (1977 - 1978 )
PLYMOUTH FURY SPORT (1977 - 1978 )
PLYMOUTH FURY SPORT SUBURBAN (1977 - 1978 )
PLYMOUTH FURY SUBURBAN (1977 - 1978 )
PLYMOUTH GRAN FURY (1980 - 1981)
PLYMOUTH GRAN FURY SALON 1980
 
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Also not to get the fur flying,but;
I wouldn't have rear DBs on my streeter S if You paid someone to put them there for me. The 10inch drums are more than adequate,are trouble free, and 2.5s last forever. Remember in most cases rear brakes are called on to do just 15 to 25 %of the braking. They are just there to satisfy the parking brake requirement, lol. Please no fur, this my personal opinion.
Sometimes a guy just wants what he wants, and there is no arguing that.
If you really like the looks of DBs in the rear and are willing to spend the coin get them there, and can get wheels to fit and showcase what your money has bought, and can stand it when they squeal for no apparent reason,etc; well then put your order in.
 
Great info. Is there substantial difference between the 10.98 and 11.75 rotors? All I have seen are 5th Ave in my area.

While I understand there is no signficant reason to move away from drums, fact is I don't have drums. I have a naked 8.75 that is going to be cut down. I will have to buy aftermarket axles. I will need brakes. Since that is the case, and I don't like seeing the drum behind a nice wheel when it's nearly the same work (for me, in this case), I might as well go disc, and paint and detail to my likings....

Thanks for all the insight and opinions.
 
Not uncommon. Chrysler used the small bolt pattern clear through to 76.
 
RustyRatRod said:
Not uncommon. Chrysler used the small bolt pattern clear through to 76.
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Does that also mean he might have the small ball joint control arms Rusty or is there a firm cut off on those? These cars are so old now and have been monkeyed with enough you probably should check your dash VIN# against the core support #s to see if it was a re-body.....
 
mguner said:
Does that also mean he might have the small ball joint control arms Rusty or is there a firm cut off on those?
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Now THAT I am not sure on. I always thought they used it all if it was small bolt pattern, control arms too, but I am not sure. The only part I am surea bout 100% is that the small bolt pattern DID go through 76.

Jim would know. 71Hemix I think is his screen name. He is real sharp on all this.
 
Backtobasics said:
Great info. Is there substantial difference between the 10.98 and 11.75 rotors? All I have seen are 5th Ave in my area.

While I understand there is no signficant reason to move away from drums, fact is I don't have drums. I have a naked 8.75 that is going to be cut down. I will have to buy aftermarket axles. I will need brakes. Since that is the case, and I don't like seeing the drum behind a nice wheel when it's nearly the same work (for me, in this case), I might as well go disc, and paint and detail to my likings....

Thanks for all the insight and opinions.
Click to expand...

There's about a 9% increase in braking force going from the 10.98's to the 11.75's, just because of the rotor diameter (larger lever arm acting on the spindle). A-body's also used smaller diameter pistons in their calipers, so if you use the later B/E/R body calipers you get an additional increase in braking force compared to the A-body calipers. And then there's better cooling because the larger rotors, while having the same brake pads and therefore the same brake pad area, have a larger rotor surface area (and swept area).

mguner said:
Does that also mean he might have the small ball joint control arms Rusty or is there a firm cut off on those?
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1972 should have been the last year for the SBJ UCA's. 1973+ should all have large ball joint UCA's, even if they had SBP drums in the front (which would have been 10"). Now, this is Ma Mopar we're talking about, so how firm a cut off that is would probably be open for some interpretation.
 
mguner said:
Does that also mean he might have the small ball joint control arms Rusty or is there a firm cut off on those? These cars are so old now and have been monkeyed with enough you probably should check your dash VIN# against the core support #s to see if it was a re-body.....
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1973 was the changeover year, after that everything had the larger upper ball joint!
 
cosgig said:
1973 was the changeover year, after that everything had the larger upper ball joint!
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I've heard that but it always seems like somebody has an exception, usually because somebody else has gotten their mitts on the car. I'm sure that Mopar tried to use up all the parts they had on these things though. I bought a slant 73 Duster body once with no doors for $75 mainly because somebody wanted big bolt pattern so bad they put the KH 340 disc setup on it from a swap! CHACHING!
 
mguner said:
I've heard that but it always seems like somebody has an exception, usually because somebody else has gotten their mitts on the car. I'm sure that Mopar tried to use up all the parts they had on these things though. I bought a slant 73 Duster body once with no doors for $75 mainly because somebody wanted big bolt pattern so bad they put the KH 340 disc setup on it from a swap! CHACHING!
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Yeah exactly. This is 43 years down the road from 1973, so who knows what someone might have done. For awhile drag racers were changing disk cars to drums because of the lower rolling resistance. And then there's former parts cars that had BBP disks swapped for '72 down drums to swap the earlier car to BBP disks and keep the "parts" car rolling. I've read posts where someone had a 73+ V8 car with front SBP drums that swore it proved they had them from the factory, but according to all the literature they didn't. Only /6 cars with manual brakes got SBP, 10" front drums from '73 to the end of calendar year 1975 (not model year!), from Jan. 1976 everything got disks up front by law. Someone just swapped them at some point, who knows why. Between that and Ma Mopar's tendency to use up leftover parts before a changeover, there's probably some exceptions out there. Or at least cars that might seem to be exceptions.
 
AJ/FormS said:
Remember in most cases rear brakes are called on to do just 15 to 25 %of the braking.
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Yup...been riding street bikes for 33 years, give or take. Have had several sport bikes that I had the rear rotor get such a glaze on from not using it that the rear brake didn't work. Always thought that rear drums on a car with front discs were just there so you had a pedal...
 
There is a way to take advantage of the rear, Put the biggest tires in there that will fit, throw the P-valve away and start swappin in rear W/Cs til you get some action back there.
You'll know when it's right by the way it stops; AWEsome.
It's like; finally getting the electric trailer-brake sensitivity adjusted right.
It's like; the car is gluing itself to the road while simultaneously trying to pitch me through the windshield.
It's like;who knew this was even possible
It's like; remember the 454Corvettes of the early/mid seventies. They had brakes!
 
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The Scarebird adapter plate bolts to your existing drum spindle, so doesn't matter what upper ball joint you have. If your car uses the same lower ball joint as earlier drum cars, the spindle "should" have the same bolt pattern.

You can save a lot if you buy just the adapter plates from Scarebird (~$110) and source the Toyota and GM parts locally or ebay/amazon.
 
Dartnut said:
....The only exception to this rule was the factory Super Stock Barracudas and Darts for 1968, which were all big bolt pattern with retrofitted b-body parts on them.
Click to expand...

Just to clarify a common misnomer/wives tale.

The disks on 68 Hemi S/S cars were NOT retrofitted Bendix B body parts. The Hemi A-bodies had special Kelsey Hays hubs and rotors machined with large bolt pattern and large hub center register. And they used the same calipers, LCA's, and UCA's as regular '68 disk brake A-bodies.
 
BillGrissom said:
The Scarebird adapter plate bolts to your existing drum spindle, so doesn't matter what upper ball joint you have. If your car uses the same lower ball joint as earlier drum cars, the spindle "should" have the same bolt pattern.

You can save a lot if you buy just the adapter plates from Scarebird (~$110) and source the Toyota and GM parts locally or ebay/amazon.
Click to expand...

It might not matter what ball joint you have, but it DOES matter what spindle you have.

All of Scarebird's conversions are for 65-72 drum spindles, and there are different versions of the kits for the 9" drums and 10" drums. No mention whatsoever of the 73+ drum spindles, and they are different. The 73+ drum spindles, like the 73+ disk spindles, have larger wheel bearings. There are several disk conversion kits for the '73+ 10" spindles that use the large ball joints. They don't work on the '72 down 10" spindles, and the ball joint taper diameter isn't the problem. One example is Doctor Diff's viper caliper conversion kit for the '73+ A-body drum spindles...Viper Caliper Mounting Brackets for Mopar DRUM Knuckles
 
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