Hi everyone, I have read a couple of articles about converting the 72 dart front drums to disk brakes by using the 73 to 76 A body car parts. I was also told that you need to replace the upper a arm since the hole is smaller and needs to be replaced. Has anyone done this before, have i got the correct information?

Nate.

 

Yep just go to a junk yard or parts car and grab the upper control arm (2 bolts) and the spindle (disconnect from the lower arm) cut the brake hose (you are going to buy a new one right?) bring the assy home clean it up, replace pads as needed. Done.

Good project and very good upgrade.

 

I almost for got will this also give me the larger 4 1/2 bolt pattern, and will the spindle be larger to hold more weight?

Thanks Nate.

 

yes you will get the larger boltpattern with that spindle which is a bit stronger.
Also, if you cannot get the upper A-arms (even if you can find one they are notorious for the mounting bolts not being able to be removed due to rust) Firm Feel Inc. www.firmfeel.com makes a set of tubular ones that are reasonably priced. These upper control arms also make the car handle a bit better. (more caster)

 

Thanks guys, this is good information. Couple more question for anyone out there. Do i need to have a vacuum booster pump to run the disk breaks for the front,or will i be fine just to install the adjustable proportional valve. I will have a larger rear end installed latter. My second question is, if i make the conversion from getting the parts form a newer car will it make the distance from the center of the car to the center of the tire increase, resulting in buying back spaced rims?

 

should not change the spacing very little, if any.
Well, you can get by without a booster. You just need the right combination of parts.
Use "slider type calipers" from a 1981 Chrysler Cordoba. Master cylinder from a 75 valiant with disc. Also the rotors from the 75 valiant and the hoses from the 75 valiant. Use the rear wheel cylinders from a 1980 Dodge 1/2 ton pickup with 10 inch drum brakes in back. (wheel cylinder should have a 7/8 bore diameter). Of course you'll have to find the spindles and attached caliper brackets in the junkyard or somewhere. (used is fine, but can be had new through Master Power Brakes).
Also you will need the lower ball joint from the 75 valiant.

 

This is rally good stuff, I appreciate the good advice. All I need to do know is gather the parts and schedule a weekend.