Rear disc brake conversion for 14" wheels

[Fair67]

As you can guess, rear disc brakes are in order for my client's 67 GT 350. He is keeping the 14" wheels. Can anyone recommend a kit that will work with these replica magstar wheels? I am only interested in a bolt on kit, so it can have the original parts reinstalled in the future, if desired. I have identified some kits out there that are compatible with 14" wheels, but I wanted to be sure there isn't something I am unaware of for this car...and these wheels. Thanks in advance!

[Cobrask8]

14"? Shouldn't they be 15"

I know of no kit that will fit a 14", there are kits for 15". Many use either the 1994 Mustang GT rear calipers with parking brake, or a GM Vette rear caliper. Not sure on the rotor. Rear brake lines will need to be changed, and other work done. Probably a bigger job than you are thinking.

You will have to change the master cylinder and remove the prop valve in order to get the correct fluid flow to the back, or the effort is wasted.

Do alot of research. Don't just ask.

[Bob Gaines]

I would think it would be time well spent convincing the owner to use 15 " wheels instead of the 14". If using Magstar style in 14" or 15" you may incounter clearance problem .  I am not aware for a replica 14" magstar wheel. Even if it were a 15" the center portion of the 15" magstar was the same center as your typical 14" wheel. The rim necks down in that area which causes clearance problems sometimes with front calipers like when used with a 68 single piton caliper. I imagine it will cause problems with calipers mounted on the rear also .

[Fair67]

Actually they are 15's  after laying eyes on them.
The 14's are on another non Shelby car. It will be getting a similar upgrade.

I have done the conversion on A 9" with 16" wheels. It was a dentside. I used the factory master cylinder and an adjustable proportioning valve to fine tune the brake bias. However, that is a truck, already had larger brake lines to the back, and is 12 years newer. It was a big improvement!

I am here asking questions....as part of my research.

[Fair67]

I would think it would be time well spent convincing the owner to use 15 " wheels instead of the 14". If using Magstar style in 14" or 15" you may incounter clearance problem .  I am not aware for a replica 14" magstar wheel. Even if it were a 15" the center portion of the 15" magstar was the same center as your typical 14" wheel. The rim necks down in that area which causes clearance problems sometimes with front calipers like when used with a 68 single piton caliper. I imagine it will cause problems with calipers mounted on the rear also .

The car with 14's are the magnum 500 wheels, but that doesn't matter here.
This car has four piston calipers on the front, but I was unaware of the construction of the magstar center you mentioned. That is why I am here. To learn from the masters! Thank you!

[Fair67]

I would think it would be time well spent convincing the owner to use 15 " wheels instead of the 14". If using Magstar style in 14" or 15" you may incounter clearance problem .  I am not aware for a replica 14" magstar wheel. Even if it were a 15" the center portion of the 15" magstar was the same center as your typical 14" wheel. The rim necks down in that area which causes clearance problems sometimes with front calipers like when used with a 68 single piton caliper. I imagine it will cause problems with calipers mounted on the rear also .

Are there similar issues with the ten spokes? I am always open to learn!

[shelbydoug]

I would think it would be time well spent convincing the owner to use 15 " wheels instead of the 14". If using Magstar style in 14" or 15" you may incounter clearance problem .  I am not aware for a replica 14" magstar wheel. Even if it were a 15" the center portion of the 15" magstar was the same center as your typical 14" wheel. The rim necks down in that area which causes clearance problems sometimes with front calipers like when used with a 68 single piton caliper. I imagine it will cause problems with calipers mounted on the rear also .

Are there similar issues with the ten spokes? I am always open to learn!

I have a '76 Lincoln Versalles rear in my car. It has a disc brake set up that is unique to the Versalles and the Granada.
I'm using 15" 10 spokes with it and it allows 295-50-15 tires to fit with a slightly lowered suspension.

I never tried it with a 14" wheel but it's possible but why would you want to?


The ORIGIGINAL (NOT REPRODUCTION) 10 spokes are much tighter on the brake side of the wheel then most any other wheel I've EVER seen, because of the way they were cast.

The current reproduction 10 spokes are machined on the inside and allow more clearances for bigger brakes.

I had to go to those on the front when I put the big Galaxie/68 trans am brakes on the car. Look to these combinations for your answers.


My original parts are all stored here and go with the car to the future caretaker. The Lincoln rear bolts right into the Mustang rear. Pirches are right there and as a benefit are more heavy duty then the orignal housing as well as being the same width as the 65-6 Mustang rear. That is 2" narrower then the 67-8 housing. That's why those tires fit within the wheel wells.

[tesgt350]

It might be too late to find one BUT, if you can find a Lincoln Versailles Rear End, they were built in the late 70's and had Rear Disc Brakes. Many Friends installed them in their 65-68 Mustangs.  I worked at an Auto Salvage Yard and bought everyone that came in and they would sell fast and I always doubled my Money. Maybe you can get the Part Numbers for the needed Parts and by those.

[Cobrask8]

I know there is a company that makes a conversion for the 9" rear, just don't know who off-the-cuff.

Remember - you will need a different master cylinder and remove the prop valve for the brakes to work correctly. The stock system sends the bulk of the brake fluid to the front. 4 wheel disc will need roughly equal to all corners.

[shelbydoug]

I know there is a company that makes a conversion for the 9" rear, just don't know who off-the-cuff.

Remember - you will need a different master cylinder and remove the prop valve for the brakes to work correctly. The stock system sends the bulk of the brake fluid to the front. 4 wheel disc will need roughly equal to all corners.

All the Versalles needs for a master cylinder is the stock one with the rear check valve removed.

The proportion of front to rear braking doesn't change.

There isn't a lot of advantage to rear disc brakes. In fact they seem to have perpetually an issue with keeping the Parking brake operable. With automatic transmission cars, that doesn't matter much because most of that is handled by the transmission.

The main advantage is quicker cooling down from repetitive stops from 100 mph or more and better water jamming resistance.

Other then that, they just look cool.


I have an entire spare Versalles here, minus the banjo, pumpkin and axles.

I would advise, should you decide to go that route, stock Versalles axles are 28 spline and you might want to consider 31 spline Strange axles?

You COULD use a stock 9" Mustang banjo with the Versalles brakes, but you might need to modify the mounting flanges slightly on it?

[Bob Gaines]

I agree that the rear disc upgrade on a 65-67 is over rated on even a high performance spirited driven street car. The big rear brakes adjusted properly are more then adequate. Talk to Cobra Automotive that competitively race those cars and see what they think?    IMHO the disc modification in this instance based on highly knowledgeable vintage racing opinion is a waste of money that could be spent elsewhere. Others may think differently.

[gt350shelb]

I agree that the rear disc upgrade on a 65-67 is over rated on even a high performance spirited driven street car. The big rear brakes adjusted properly are more then adequate. Talk to Cobra Automotive that competitively race those cars and see what they think?    IMHO the disc modification in this instance based on highly knowledgeable vintage racing opinion is a waste of money that could be spent elsewhere. Others may think differently.

+1  and the lack of adequate parking brake  in all the versions .

[Fair67]

Thanks for all the Intel!
The wealth of knowledge y'all have is awesome!

[C6ZZGT]

I also run the Versailles rear end on my 66 GT Coupe,and have since the early nineties,I have zero issues with the park brake operation. I also run 14 inch steel wheels.

[shelbydoug]

I also run the Versailles rear end on my 66 GT Coupe,and have since the early nineties,I have zero issues with the park brake operation. I also run 14 inch steel wheels.

Mine won't hold on a hill. Is your car automatic or manual transmission?

I keep wanting to go into the parking brake assembly and play with the size of the bearing balls that actuate the piston. So far, I keep finding other things to do?

I think that is the fix. The ball bearings that are in there are too small in diameter and need to be bigger to press on the piston harder? If so, that's an easy fix.

The other thing with that parking brake is it was designed for the Lincoln with a foot actuated lever in the cockpit. The hand lever of the Mustang needs some consideration as to how to hold it firmer in place when actuated.