4 piston to single piston swap. 72 Demon

-

Woodie

Take-off EH!
Joined
Feb 10, 2012
Messages
448
Reaction score
156
Location
Ontario
I Planning on swaping out the factory 4 piston set- up currently on the Demon in favor of a single piston set up I took off of a 73 Dart sport. Reason for this is I have SBP on the front and LBP aftermarket axles on the rear. Are the front spindles the same? Also curious if I use the same factory upper control arms as well. Will the brake proportioning still be the same?

Thanks.
 
I Planning on swaping out the factory 4 piston set- up currently on the Demon in favor of a single piston set up I took off of a 73 Dart sport. Reason for this is I have SBP on the front and LBP aftermarket axles on the rear. Are the front spindles the same? Also curious if I use the same factory upper control arms as well. Will the brake proportioning still be the same

Thanks.

No, spindles are not the same.
Two totally different brake designs.

You will need to change over your upper control arms to 73-76 large ball joint ones, and change your lower ball joints over to 73-76 ones.
 
Last edited:
No, spindles are not the same.
Two totally different brake designs.

You will need to need to change over your upper control arms to 73-76 large ball joint ones, and change your lower ball joints over to 73-76 ones.
Thanks for the info. Need to source a set of upper control arms. I have everything else.
 
There are adapter bushings for the spindle holes that let one use the smaller ball joint and matching upper arm in the larger spindle hole. I haven't used these bushings. I'm not recommending them. FYI only.
 
There are adapter bushings for the spindle holes that let one use the smaller ball joint and matching upper arm in the larger spindle hole. I haven't used these bushings. I'm not recommending them. FYI only.
Thanks for the input Redfish. Thinking of going aftermarket "Tubular".
 
ball joint adapter is the way I'd go if the small ball joints and uca bushings are newer. DrDiff carries them.
No getting around replacing the lower.
73-76 A body lower ball joint, same piece disc or drum.
 
ball joint adapter is the way I'd go if the small ball joints and uca bushings are newer. DrDiff carries them.
No getting around replacing the lower.
73-76 A body lower ball joint, same piece disc or drum.
Thanks Jimacuda.
 
why not just use Mustang rotors and keep everything you currently have
 
Sooooooooooo
What's wrong with different bps front to rear? I've been doing that for decades.
You know those 4-piston calipers are fabulous for a streeter. No sliders to wear out or pins to jam up, and pad replacements take mere minutes. Or hey, if one pistons freezes up in winter, due to moisture, there are still 3 others to get the job done,lol.
I really like my KHers. And I'm OK with 14x7s up front and 15x10s out back.
As to proportioning, that depends more on what your rear rubber can handle.My P-valve is gutted, and the rear could handle even more pressure.
Seems like a lotta work, for what I would call a minor gain.
But if you are wanting to run 4 same-size, interchangeable, wheel assemblies; that I can understand.
 
Sooooooooooo
What's wrong with different bps front to rear? I've been doing that for decades.
You know those 4-piston calipers are fabulous for a streeter. No sliders to wear out or pins to jam up, and pad replacements take mere minutes. Or hey, if one pistons freezes up in winter, due to moisture, there are still 3 others to get the job done,lol.
I really like my KHers. And I'm OK with 14x7s up front and 15x10s out back.
As to proportioning, that depends more on what your rear rubber can handle.My P-valve is gutted, and the rear could handle even more pressure.
Seems like a lotta work, for what I would call a minor gain.
But if you are wanting to run 4 same-size, interchangeable, wheel assemblies; that I can understand.
..I agree with the with your thoughts.. I have Centerlines front and rear. I want to run a set of Cop wheels with 15x6 up front an 15x10s on the rear for a Nasty look. I have a complete set of 73 front discs, spindles minus the Upper Control arms. (I gave them to a friend in need a while back) just seeing what my options are. Also i feel its time to rebuild the entire front end, pull it apart and make it new again.
 
I forgot to mention;
I was so busy finding fault with the 73Up stuff, that it slipped my aging mind. The KH stuff has been trouble-free for me to the tune of 17 years and 125,000 plus miles. That's Zero maintenance required.And no, I have never had a moisture issue with DOT5.Nor the so-called compressibility.I do have the Teflon-lined front hoses. Awesome street brakes with the 10 x 2.5s and 295s out back doing a good portion of the work!I have never had a car that braked; better, harder,or in a shorter distance.And I think I may have only ever been in one other comparably stopping street car,since 1969. I think all cars should have bigger tires and harder working brakes, out back. I mean think about what that P-valve is doing. It is preventing the rear from skidding the tires and initiating a spin.Wouldn't more rubber back there have been a better idea? I thought so, and that's partly why I worked so hard to get the bigger boots back there. Well that and spinning out on every turn-under-power, was getting old........lol
 
-
Back
Top