74 dart drum sbp to lbp disk

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moparkid340

moparkid340

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Hello i need some help i have a 74 dart with small bolt pattern and drums up front i want to swap it to large bolt patteren disk with junk yard parts my local pull apart has a few diplamats and cars like that with disk. Well this swap work without any fabracation? If so what all do i have to switch from the doner car? Thank you
 
Hello there,
The Diplomat/Gran Fury/5th Avenue cars all use the same knuckle/spindle and will bolt into your car just fine. The Aspen/Volare cars are the same as well. You will need lower ball joints for a 73-76 Dart with disc brakes. If your car was equipped with the 10" front drums, you are good to go. If the front drums are the 9" size, you will then also need to get different UPPER control arms. The disc and 10" drum cars used the UCA with the larger upper ball joint, which was the same one used in the B and E body cars.
Be careful about how you route the brake hoses! The factory arrangement for a 73-76 Disc a body is with the calipers mounted forward of the hub. The donor cars you mentioned mount them to the rear. The rear location often results in the hoses bunching up in a loop, and they can rub the tires and wear through eventually.
Greg
 
Grab the proportioning valve(disc brake)also the master cylinder as it will be for disc,not drum brakes.:thumblef:
 
.you can get ball joint spacers from 'doctor diff and use your small ball joint upper A arms
.page him on Moparts
.if you use your drum master cyl, take out the residual valve on the disc reservoir and check the level ocassionaly.As the pads wear they will displace more fluid than the drum
side
 
Just grab the spindles, calipers, caliper brackets, proportioning valve and master cylinder from the Diplomat. Pretty easy, just bring a pickle fork, bfh, 3/4" wrench, 3/8" line wrench (or just cut the brake hoses, you'll probably want new ones anyway), and a pair of pliers for the cotter pins and you should be able to grab the spindles and everything attached to them. Throw in some 1/2" tools and you should be able to grab the master and prop valve.

You shouldn't need sleeves to adapt the ball joints, pretty sure the later drum cars used the big ball joint uppers. And the lowers should be the same unless they're 9" drums, but I believe the later cars were all 10".
 
Hey Guys got a question...

I go and get the complete disc brake set up off of a 88 Fifth Avenue...but when I get every thing off of the 72 Dart I have a major concern. I know I removed the knuckle arm off of the lower control arm ball joint of the fifth avenue. but when i go to connect the knuckle arm to the lower control arm of the Dart i'm confused about where the ball joint is suppose to go.:banghead:
Are they even compatible?
Am I switching the lower control arms also?
 

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You need a set of lower ball joints for a '73+ disk equipped A body, the 5th ave ball joints won't work (obviously!). Bolt spacing on the A body joints is the same, so they bolt right up.

Lower control arms stay, 5th ave lowers are not compatible.

You'll also need a longer set of bolts for the '73+ a-body lower ball joints, the A body lowers aren't threaded like those are so they need a nut.
 
Frankenduster said:
Hello there,
The Diplomat/Gran Fury/5th Avenue cars all use the same knuckle/spindle and will bolt into your car just fine. The Aspen/Volare cars are the same as well. You will need lower ball joints for a 73-76 Dart with disc brakes. If your car was equipped with the 10" front drums, you are good to go. If the front drums are the 9" size, you will then also need to get different UPPER control arms. The disc and 10" drum cars used the UCA with the larger upper ball joint, which was the same one used in the B and E body cars.
Be careful about how you route the brake hoses! The factory arrangement for a 73-76 Disc a body is with the calipers mounted forward of the hub. The donor cars you mentioned mount them to the rear. The rear location often results in the hoses bunching up in a loop, and they can rub the tires and wear through eventually.
Greg
Click to expand...

The calipers are often put on the back of the a bodies with no problem so the early sway bar can be used.
 
MemphisDart said:
Oh well back to square one:sad7::sad7:
Click to expand...

Not at all!

You have everything you need except for the lower ball joints, which can get at just about any parts store. With the '73+ A body lower ball joints the rest will bolt right up.
 
72bluNblu said:
Not at all!

You have everything you need except for the lower ball joints, which can get at just about any parts store. With the '73+ A body lower ball joints the rest will bolt right up.
Click to expand...

ok so i need this
 

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MemphisDart said:
ok so i need this
Click to expand...

Exactly! :D

And, a set of bolts to mount them up. They'll be the same diameter and thread as the ones attached to the 5th Ave ball joints, but they'll need to be about 3/4" longer because the A body lower ball joints are not threaded like the 5th ave pieces are.

Also, the stock bolts that served this purpose have a thinner head. I would just buy a set of grade 8's at the hardware store, but keep in mind you may need to grind the heads thinner to get enough clearance on the rotor. Or, find a stock set of lower ball joint bolts for a 73+ disk brake car. Not a big deal, but do a test fit and check clearance if you go the grade 8 route.


**EDIT**

Nevermind, saw that you have a SBP disk brake car already. Not 100% positive, but I believe you may be able to use your old lower ball joint bolts. The ball joints themselves are different, but the bolts should be the right length. I've never had a SBP disk set up, so I'm not sure if they're the same diameter though.
 
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