1973 Dart Swinger Drum to disc

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metalbender58

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I'm new to FABO site so I hope this is the right place for this post. I recently picked up a 73 Dart Swinger with front drums. The car was a 6 cylinder that has a 5.9L swapped in. I want to swap to disc in front. From what I was able to gather in my research Mopar used the same rotors, calipers, bearings, etc, in a variety of models over several years. Just wondering if that information is correct and what issues I may run into. Thank you
 
1.Get all the parts off a 73-76 A body with discs, will bolt right in

2. Factory discs off a Volare/Aspen
With some mods

3. Dr Diff has kits

4. Plenty of other manufacturers with kits
 
Congrats and welcome aboard.
Rule #1: post pictures of your car. The best way to share. A lot of us enjoys seeing your new ride.
 
keep in mind wheel bolt patterns-- small bolt 5X4 and big bolt 5X4.5
you may currently have the SBP, and most disc brake kits are BBP so you'll need rims and to figure out your rear end so you don't have to carry two spares.

also, selection, sizing and price of BBP rims is much much better than SBP.

verify what you've got first and then you can plan a course of action. there are tons of options available, it just depends on what your budget is and how mechanically inclined you are.
 
Thank you all for the information on swapping to disc brakes.
I checked out the Dr Diff website and also CPP website. I don't know about Dr Diff but CPP has a complete B body kit including booster, MC and upper control arms that looks promising. I suspected the BC was different and prefer the LBC. I plan on upgrading the anemic 7.25 open diff with an 8.75 posi, if I can find a housing and will go with LBC axels. I already replaced the original 4 leaf rear springs with 6 leaf. Still debating on changing out the .82 torsion bars to .87 or larger. Definitely adding a sway bar and upgraded shocks.
I added pictures of the car after changing out the leaf springs and spending 6 hours buffing out the paint.

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yes, you should upgrade your t-bars. if you don't have a sway bar, add that to the list.

i would avoid going any bigger than .920 bars unless you want to upgrade your shocks to something a little more high end
 
whats the plans for the car? if mostly for the street I'd go 1" bars minium.
Mostly this will be a street cruiser, but there are a lot of winding streets in my neighborhood. I have looked at 103 bars but am concerned the ride will be too stiff even with high end shocks such as QA1 or KYI.
 
Mostly this will be a street cruiser, but there are a lot of winding streets in my neighborhood. I have looked at 103 bars but am concerned the ride will be too stiff even with high end shocks such as QA1 or KYI.

1.03 will not be harsh with good shocks. they will be firm but not harsh.. hell bergman autocraft a board sponsor sells 1.09 i think it is..
 
Thank you all for your input. It sounds like there are a lot of different opinions and options. I had a 73 Dart Sport 340 many years ago. I don't know what T bars it had, probably .87s. The previous owner had tightened the T bars to give the car a more aggressive stance and it handled amazing with stock shocks. I think I start with a sway bar and see what that does. See if I can score a pair of .87s at Mopars in the Park swap meet tomorrow.
 
I’d never go anything less than 1” bars on the street. I ran 1” bars briefly on my duster, even with just 225/60/15’s and the blue Monroe shocks the ride was still pretty soft. I’ve been running 1.12” bars on the street now for years, with Hotchkis fox shocks. The ride is similarly to a modern performance car. The factory torsion bars are only ~100 lb/in, most econo box commuter cars are more like 200 lb/in nowadays. Which is what the 1” bars are. The 1.12’s I run are 300 lb/in. My set up is probably more AutoX than street, but, I use it as a street car. Hell I basically use it as a commuter most of the year.

Remember the stock torsion bars were for bias ply tires. The lack of traction also meant lower wheel rates. Improve the traction of the tires and you transmit more force to the suspension, which means higher wheel rates to deal with those additional loads. Even the basic all season radials most run on these cars have a ton more traction than the old bias ply’s did. And some of it was the style at the time, soft floaty suspension was the thing in the ‘70’s. These cars were massively undersprung in the front from the factory.
 
Verify what you actually have. I believe that in '73 the 10" SBP drum spindle has the BBP ball joint which fits the later disc spindles.
 
Has anybody used the 10.95 Stage 1 front brake kit from Doctor Diff? I want to know if I can stay with 14 inch wheels using this kit. I found out CPP kit would require going to 15 inch wheels. I' rather not do that.
 
Has anybody used the 10.95 Stage 1 front brake kit from Doctor Diff? I want to know if I can stay with 14 inch wheels using this kit. I found out CPP kit would require going to 15 inch wheels. I' rather not do that.
those should fit under 14's, it's a stock spindle and caliper so that's a fixed position even though the disc is slightly larger than OE.

fwiw i ran stock 14" BBP rally's on the stocker discs with sliders (basically exactly the same set up)
 
Thanks. I had a 73 Dart Sport that had front discs and I had 14” mags on it. Just don’t remember if it was SBP or LBP
 
Thanks. I had a 73 Dart Sport that had front discs and I had 14” mags on it. Just don’t remember if it was SBP or LBP
Slants still had Small Bolt in 73 if drum. But if disk had Large Bolt and 14 inch.
My 1973 340 is disk and had large bolt 14 inch wheels
Also since 340 car had 8 1/4 321 sure grip.
When I swapped it to 8 3/4 could not give the large bolt 8 1/4 away.
No one wanted to change to large bolt on their A Body locally.
 
Slants still had Small Bolt in 73 if drum. But if disk had Large Bolt and 14 inch.
My 1973 340 is disk and had large bolt 14 inch wheels
Also since 340 car had 8 1/4 321 sure grip.
When I swapped it to 8 3/4 could not give the large bolt 8 1/4 away
No one wanted to change to large bolt on their A Body locally.
 
That tracks with what I had in my Dart Sport. It was a 340 car. The Swinger I have now was a slant six car and has manual drum brakes with SBP
 
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