Disc brake upgrade

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John Cailey

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I have a 74 Duster. Originally a slant 6 car, so original drum brakes all around. I would like to upgrade to front disc brakes now that it has a transplanted V8 Magnum motor in it. I would like to buy a kit that would include all necessary hardware, including hydraulics. Like to stick with manual hydraulics. Existing wheel bolt circle is 5 on 4". Any suggestions would be appreciated. Thanks, John
 
I did the swap on my '70 duster a few years ago went with Wilwood some of the "best" money I ever spent no need to change the upper control arms like other kits,everything bolted right on you can retain your 4-bolt pattern or upgrade to 4 1/2 if you want the rotors/hubs are drilled for both bolt patterns and I still have manual brakes noticed a HUGH difference over the stock drum brakes..:thumbsup::thumbsup:
 
I did the swap on my '70 duster a few years ago went with Wilwood some of the "best" money I ever spent no need to change the upper control arms like other kits,everything bolted right on you can retain your 4-bolt pattern or upgrade to 4 1/2 if you want the rotors/hubs are drilled for both bolt patterns and I still have manual brakes noticed a HUGH difference over the stock drum brakes..:thumbsup::thumbsup:
I did exactly the same thing. Also upgraded to the Wilwood master cylinder. I had the original Kelsey Hayes disk brakes but these stop WAY better than the Kelsey Hayes ever did. Just a note if anyone has to upgrade from the Kelsey Hayes to Wilwoods, you will have to downgrade your spindles and lower ball joint to drums.
 
I did the swap on my '70 duster a few years ago went with Wilwood some of the "best" money I ever spent no need to change the upper control arms like other kits,everything bolted right on you can retain your 4-bolt pattern or upgrade to 4 1/2 if you want the rotors/hubs are drilled for both bolt patterns and I still have manual brakes noticed a HUGH difference over the stock drum brakes..:thumbsup::thumbsup:

I did exactly the same thing. Also upgraded to the Wilwood master cylinder. I had the original Kelsey Hayes disk brakes but these stop WAY better than the Kelsey Hayes ever did. Just a note if anyone has to upgrade from the Kelsey Hayes to Wilwoods, you will have to downgrade your spindles and lower ball joint to drums.

You guys got me thinking about the Wilwood's. Here's the kit for my 70 Swinger (which really could use disc brakes)

Wilwood Disc Brakes - 1970 Dodge Dart 10" Inch Drum Brake Spindle - Front Brake Kit No.: 140-11023-DR
 
I'm strange, so I went with Strange. I also want to be different. (lightweight race hardware)
(it does come with a cap.) $795
IMAG0479.jpg
 
I went with the solid rotors..either way top notch stuff why anyone would go with the old factory crap is beyond me,you certainly get what you pay for:thumbsup::thumbsup:
 
I went with the solid rotors..either way top notch stuff why anyone would go with the old factory crap is beyond me,you certainly get what you pay for:thumbsup::thumbsup:

Yep, I'm as frugal as they come, but didn't want to skimp in this area either. Feels good to be able to take the second return road ;)
 
I have a 74 Duster. Originally a slant 6 car, so original drum brakes all around. I would like to upgrade to front disc brakes now that it has a transplanted V8 Magnum motor in it. I would like to buy a kit that would include all necessary hardware, including hydraulics. Like to stick with manual hydraulics. Existing wheel bolt circle is 5 on 4". Any suggestions would be appreciated. Thanks, John


We offer a couple of different options for your 74 Duster. Plus we offer free shipping and a Mopar forum member discount as well.

Here is a link to get you started:

PST | Disc Brake Conversion | Disc Brake Kit | Disc Brakes

Thanks
James From
PST
 
There is a big discussion on slotted verses solid brake rotors, the gist of it for a street car solid rotors are more than adequate. But having said that I used slotted rotors for the "show" effect.
 
SSBC has kits for most Mopars. I used their disc brake kits on the front and the rear of my '69 Dart. They fit and were not too difficult to install. Their front rotors have both 4" and 4.50" bolt patterns in them.
 
Just FYI, if you think you’re going to use those wilwoods with your current SBP rims you’re probably mistaken. The hub diameter on the wilwood kits now is gigantic. They redesigned their hubs a couple years back and increased the hub diameter. They won’t work with any of the original SBP drum brake wheels.

Also, regardless of the kit you use, make sure its for the right drum brake spindle. There are two different 10” drum spindles, the ‘73+ drum spindles have a different inner diameter and use different wheel bearings. The 73+ spindles also use the larger upper ball joint, so if you wanted to upgrade to the 73+ BBP disks you wouldn’t need to change your UCA’s, you already have the large ball joint uppers.

The SBP brakes are a waste of time IMHO. Lots of money to keep a bolt pattern with almost no rim selection. And limited parts availability for the rear drum brakes too, it’s “ok” now but there have been years where you couldn’t get anything other than NOS rear drums. And if you go wilwood there’s a good chance you’ll need new rims anyway, so you might as well bite the bullet and upgrade to BBP and have better brakes all around.
 
I went wilwood and bought them rom RMS.

I agree, while not needed the slotted or drilled look is worth the few extra bucks.

10247442_10204960777208567_5789213035223384309_n.jpg
 
Just FYI, if you think you’re going to use those wilwoods with your current SBP rims you’re probably mistaken. The hub diameter on the wilwood kits now is gigantic. They redesigned their hubs a couple years back and increased the hub diameter. They won’t work with any of the original SBP drum brake wheels.

Also, regardless of the kit you use, make sure its for the right drum brake spindle. There are two different 10” drum spindles, the ‘73+ drum spindles have a different inner diameter and use different wheel bearings. The 73+ spindles also use the larger upper ball joint, so if you wanted to upgrade to the 73+ BBP disks you wouldn’t need to change your UCA’s, you already have the large ball joint uppers.

The SBP brakes are a waste of time IMHO. Lots of money to keep a bolt pattern with almost no rim selection. And limited parts availability for the rear drum brakes too, it’s “ok” now but there have been years where you couldn’t get anything other than NOS rear drums. And if you go wilwood there’s a good chance you’ll need new rims anyway, so you might as well bite the bullet and upgrade to BBP and have better brakes all around.
Thanks for that info 72bluNblu. Wheel clearance is not an issue. Running 15x7 Americans up front with a inside rim Dia. big enough to take Wilwoods largest rotor ( per their clearance chart ). Since it is a 74, assume my UCA's have the larger ball joints? along with the larger spindle wheel bearings? The ball joints are screw-ins, but I don't know how to prove they are the larger ones? Rear brake up-grade will happen down the road when I dump the 7 1/4 for an 8 3/4.
 
:lol:Yes, trying to stop a "Land Yacht" at a tick under 130 was always - interesting. It did have LARGE factory brakes though.

Love your ride! that's the coolest car I've seen in quite a while!
 
Thanks for that info 72bluNblu. Wheel clearance is not an issue. Running 15x7 Americans up front with a inside rim Dia. big enough to take Wilwoods largest rotor ( per their clearance chart ). Since it is a 74, assume my UCA's have the larger ball joints? along with the larger spindle wheel bearings? The ball joints are screw-ins, but I don't know how to prove they are the larger ones? Rear brake up-grade will happen down the road when I dump the 7 1/4 for an 8 3/4.

As a ‘74 your car should have the later drum spindles and the large ball joint UCA’s. The easiest way to tell is to measure the ball joint flat to flat, the LBJ’s take a larger socket. I don’t remember the size off the top of my head but I’m sure it’s posted here somewhere.

:lol:Yes, trying to stop a "Land Yacht" at a tick under 130 was always - interesting. It did have LARGE factory brakes though.

View attachment 1715348341

Those factory 11 3/4” disks will outstop those cute little wilwoods everyday all day. And don’t let anyone with front runners tell you different. You want to really test some braking power run 275’s up front.
 
As a ‘74 your car should have the later drum spindles and the large ball joint UCA’s. The easiest way to tell is to measure the ball joint flat to flat, the LBJ’s take a larger socket. I don’t remember the size off the top of my head but I’m sure it’s posted here somewhere.



Those factory 11 3/4” disks will outstop those cute little wilwoods everyday all day. And don’t let anyone with front runners tell you different. You want to really test some braking power run 275’s up front.
Yes, those 79 300's came with a lot of neat police package stuff - brakes were one. When I was racing, I converted them to manual brakes on that car and still had plenty of brakes to stop it.
 
I have a 74 Duster. Originally a slant 6 car, so original drum brakes all around. I would like to upgrade to front disc brakes now that it has a transplanted V8 Magnum motor in it. I would like to buy a kit that would include all necessary hardware, including hydraulics. Like to stick with manual hydraulics. Existing wheel bolt circle is 5 on 4". Any suggestions would be appreciated. Thanks, John

Disc O Tech article is the best starting point. You'll need to convert to 5 on 4.5 to get good brakes. I'd say the factory 11.75 rotors with 15 inch wheels is the absolute minimum brake system for a street driven car. DISC-O-TECH: Stop on a dime from Mopar Action and Rick Ehrenberg
 
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