Thoughts on Drum to Disc Conversions…

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Right. Because there are other things in this case that can make it an escalating project. Such as, the car will be used for long trips and with 4.5x5 bolt pattern on the fron and 4 x 5 on the rear, do you want to pack two spare tires? The 10" drums are OK for most normal purposes. Trailer towing or lots of steep mountain decents, and the better cooling of the disks will be an advantage.

With good linings, properly setup drums will stop fine on the highway. Its the repeated high speed stops where the heat can't be dissipated as fast.
 
Portfield will line shoes. Will arc them too. I use their street compound on the rear shoes and the front pads. I'm sure there are cheaper options too. Many over the counter shoes will have a friction lining manufacture's edge code. Those will include a two letter code which gives a rough indication of how effective it is. So if you're looking at parts store pads or shoes, check those. You want at least in the range of the original linings.
 
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sccachallenger said:
Many new owners of all drum cars have no idea how they're supposed to stop, like when new.
Before I spent money on converting to front discs I'd make sure my 4 drums were working properly.
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Hell, Vixen's got all 9" drums all around and she stops fine.
 
Ya Wilwoods are a nice product, once you toss some of their inferior attachment nuts that they come with, but IMHO they don't stop any better than drums do and wish the guy I got my Dart from hadn't thrown out the original front drums.
 
Good grief. The drums aren’t that great. My ‘71 GT had 10” drums on it, I fully rebuilt them and drove the car before I took it down to rebuild the engine. I’ve had several 50’s era cars that ran 4 wheel drums for at least awhile. I’ve had them all working and stopping properly as designed.

And you couldn’t pay me to run a 4 wheel drum car around on the freeway for any length of time. Disks are superior technology. They maintain equal braking better than drums with auto adjusters, they work better in the rain and resist brake fade better. And then there’s finding good replacement parts for the drums, because they’re not always available.

If you’ve got a show pony and all you do is putt around to an occasional show or Dairy Queen or something fine. But if you’re doing much more than that and are running around with drums you better remember that it’ll take you significantly longer to stop than every other car on the road, and those other cars definitely won’t take that into account.
 
Most drum brakes don't work good because people neglect them just like everything else. If they're maintained and in good shape, they can work surprisingly well. Yes, they fade if pushed beyond their limit, but as long as they're in their element, they work pretty darn good.
 
72bluNblu said:
The best “bang for your buck” would be going with the 73+ style disk kits that use factory replacement parts. @DoctorDiff is the place to go. Yes, you can probably find a cheaper version of the 73+ kit elsewhere, but you will also get cheaper parts-bearings, lines, pads, etc. DoctorDiff’s kits use quality parts that will be better in the long run. You can use either 10.95” or 11.75” disks with the 73+ kits. If you use 15” rims the 11.75’s will fit and provide a nice upgrade in stopping power

As for the Wilwoods, keep a few things in mind
- they have less clamp force at the caliper than the 73+ Mopar calipers do
- the hub diameter is over 3”, which means they will not work with factory BBP wheels. Aftermarket wheels only. And check, because not all aftermarket wheels will fit them either
- they use a 2 piece aluminum hub that must be safety wired together. It’s an extra step, and if you’ve never safety wired anything before it does take some practice to do it correctly
- parts can be ordered, but won’t likely be stocked by most local parts shops. This is less of an issue now than it used to be, as the 73+ stuff isn’t always on shelves all the time like it used to be.
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Just run that Dr Diff stage II kit with 11.75 rotors

But you will need large ball joint upper control arms. Like: Mopar Upper Control Arms

Or run that spacer Dr Diff sells: Mopar A-Body Upper Ball Joint Tapered Adapter
 
I grew up in the area, 35 years of so cal drivers ed.

You can always not tailgate!

Here is Northern Colorado when ever it rains or snows there are pileups. 100% convinced from watching typical dry weather driving habits it's the tailgaters that cause the accidents.
 
Dana67Dart said:
I grew up in the area, 35 years of so cal drivers ed.

You can always not tailgate!

Here is Northern Colorado when ever it rains or snows there are pileups. 100% convinced from watching typical dry weather driving habits it's the tailgaters that cause the accidents.
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True. I lived in Midwest too.

There’s just tighter spacing in LA Metro traffic in general. You leave too fat of comfortable gap in high congestion traffic and someone will pop in and fill it.
 
Don't know if it was mentioned, I didn't have time to read at all the posts, but if you go to the large bolt pattern on the front, you will have to swap the rear axles, drums, backing plates, etc. to large bolt pattern also, or carry two spares with both large & small bolt patterns.
 
Save your 10" spindles. Those are the one's you want to use with the wildwood kit if you go that route.. 9" are weaker. I converted my Drums to Kelsey Hayse set up and love them. 4" BP. Parts still can be found. I have two caliper assemblies all rebuilt and on the shelf if I get in a jam and need one. One extra hub too as they are tough to find. If you don't mine 4.5 BP the stock 73-? disc brake in my opinion work great. You would need the whole spindle assemblies and Upper control arms as said.

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Sublime one said:
Go to Wilwood site, you can learn gobs there even if you don’t purchase their product. They are a bit higher priced but the parts fit like they should and zero issues. And they supply everything you need for conversion. Just my opinion but brakes is the one place I will not cut corners or go with lesser quality. But keep in mind I race most of my junk and if you want to go fast you darn sure better be able to stop.
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I used the wilwood drum to disc conversion with my small ball joint spindles. Great kit, no complaints. Put it together myself, and i'm no expert mechanic.
 
Its 2022, so the average vehicle made in the last 10 years can do 60-0 in about 120ft, some more performance cars are around 100ft.

You have a good set of stock 73+ style brakes with good pads and decent tires, maybe you can modulate your way to 130-140ft from 60. Makes it pretty safe, and they have some repeatability if you have to do more than one stop.

You have drums on all 4, they might get 1 stop in the 150ft range, if you can keep it from locking. Then up and up from there. Even the best ones probably have very narrow tires. Might be the difference between plowing through another car and not. I had perfectly working 10" drums and if you really needed to stop it would basically just skid the tires because they were 195s on tiny rims and they are more difficult to module. Even the stock disks (and the wider rubber) saved my car from hitting a few deer over the years as well as from people driving like jerks on the road. This was even when I had stock disks and 225's.

Now I have Dr Diff 13" Cobra Fronts and 11.75 Cobra rears and now I have to worry about getting rearended...
 
dadsbee said:
Ya Wilwoods are a nice product, once you toss some of their inferior attachment nuts that they come with, but IMHO they don't stop any better than drums do and wish the guy I got my Dart from hadn't thrown out the original front drums.
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Totally DISAGREE I had drums on the front of my duster switched over to Wilwoods its like night and day duster stops wayyyyyyyyyyyyyyyy better now!!
 
I used the SSBC kit on my '71 Dart GT. SSBC allows small or large bolt pattern wheels. It does push the front wheels outboard ~1/4" (if I remember correctly). It was expensive, but it was a complete kit with good directions. I would use them again. My $.02 opinion!
 
I am going to use early 4 piston Kelsey Hayes brakes . On the Demon staying 4" small bolt and 15 inch Cragars . On the Barracuda if we do it same brakes but with 68 mustang big bolt 4 1/2" rotors and Torque Thrust wheels. I like the early 4 piston brakes there is no drag when released. Less brake dust. also leaves the wheel base narrow as they came from 67-72
 
stroked340 said:
Totally DISAGREE I had drums on the front of my duster switched over to Wilwoods its like night and day duster stops wayyyyyyyyyyyyyyyy better now!!
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Sometimes comparisons can be misleading. If your last date was the Wicked Witch of the West, any woman looks good now.
 
goldduster318 said:
Now I have Dr Diff 13" Cobra Fronts and 11.75 Cobra rears and now I have to worry about getting rearended...
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^^This plus the far better tire compounds, tread design and construction of 17" or 18" over what you can get in 15".

After driving a 66 Coronet 500 with a 440 and 4 wheel, 10" drums (completely new on all 4 and the master) several years in the the rain, snow and heat of Oregon, I'll tell you drums suck. A trip down the Columbia Gorge in a down poor turn braking into a plan a head operation, like start applying brakes about a mile before the exit so they would actual work when you got to the stop sign.

To the OP, call or email Dr. Diff. Cass will set you straight and answer any questions you have, and will support his products after the sale.
 
Oldmanmopar said:
I am going to use early 4 piston Kelsey Hayes brakes . On the Demon staying 4" small bolt and 15 inch Cragars . On the Barracuda if we do it same brakes but with 68 mustang big bolt 4 1/2" rotors and Torque Thrust wheels. I like the early 4 piston brakes there is no drag when released. Less brake dust. also leaves the wheel base narrow as they came from 67-72
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And if your pads start wearing down you slap a set of pads in in about ten minutes as long as the rotors are good .
 
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