Wilwood Brakes on a 67 Plymouth Valiant

[Aussie Kel]

Hi, I have just discovered this site after I purchased a Wilwood front disc conversion kit which is supposed to be an easy conversion using the old drum brake stubs for my 67 Plymouth Valiant. Has anyone had any dramas with this conversion kit?

Why the conversion? Bit concerned the drums will have a bit of trouble pulling up the 440 in it

 

[72bluNblu]

The “drama” that usually comes up involves what wheels you want to run. The wilwood conversion has a large hub register, which requires any wheels you use to have a center bore of at least 3.050”. Which means that there are no factory or factory reproduction wheels that will fit when using that kit. Aftermarket wheels only, and only if they have a 3.050” center bore. It eliminates a lot of choices.

The only other “drama” has to do with the drum brake spindles. If you currently have 9” drum brake spindles, the lower ball joint bolts are small and have been known to fail. If you have 10” drums, no worries. I personally wouldn’t waste my money to use a kit that uses a 9” drum spindle, because if the point is to upgrade your stopping power to handle increased performance then you’ll also want to upgrade those spindles.

 

[Aussie Kel]

The “drama” that usually comes up involves what wheels you want to run. The wilwood conversion has a large hub register, which requires any wheels you use to have a center bore of at least 3.050”. Which means that there are no factory or factory reproduction wheels that will fit when using that kit. Aftermarket wheels only, and only if they have a 3.050” center bore. It eliminates a lot of choices.

The only other “drama” has to do with the drum brake spindles. If you currently have 9” drum brake spindles, the lower ball joint bolts are small and have been known to fail. If you have 10” drums, no worries. I personally wouldn’t waste my money to use a kit that uses a 9” drum spindle, because if the point is to upgrade your stopping power to handle increased performance then you’ll also want to upgrade those spindles.

Excellent, thanks for the info.

 

[Frank Mopar]

The only other “drama” has to do with the drum brake spindles. If you currently have 9” drum brake spindles, the lower ball joint bolts are small and have been known to fail.

Ball joints are the same for 9 or 10”. The only difference is the size of the spindle.

 

[72bluNblu]

Ball joints are the same for 9 or 10”. The only difference is the size of the spindle.

Not the lower ball joints. The bolts that hold them to the spindle are a smaller diameter for the 9” drums.

 

[Frank Mopar]

Not the lower ball joints. The bolts that hold them to the spindle are a smaller diameter for the 9” drums.

If you look up the ball joint numbers they all take the same ball joint. I did the exact swap so I can tell you they are the same.

 

[cudamark]

It's the disc brakes that use a different ball joint and attaching bolts.

 

[cudamark]

To me, the weak point on the 9" brakes is not only the spindle, but, the wimpy wheel bearings used with the 9" brakes.

 

[Mopar Tim]

Not the lower ball joints. The bolts that hold them to the spindle are a smaller diameter for the 9” drums.

They have to be drilled out......

 

[72bluNblu]

Ball joints are the same for 9 or 10”. The only difference is the size of the spindle.

If you look up the ball joint numbers they all take the same ball joint. I did the exact swap so I can tell you they are the same.

You're right, at least for the '72 and down drum ball joints. Both the 9" and 10" drum lower ball joints use 1/2" bolts, the 67-72 KH disk spindle lower ball joints use 9/16".

I must have been thinking 73+, those 10" drums use the same lower ball joints as the 73+ disks and have even larger 5/8" diameter bolts . The also use the larger wheel bearings and the 73+ drum spindles had large upper ball joint tapers as well.

To me, the weak point on the 9" brakes is not only the spindle, but, the wimpy wheel bearings used with the 9" brakes.

Yup, the 9" drums use smaller outer wheel bearings than the 10" drums did. They also have the "gooseneck" looking design on the spindle. I still wouldn't use 9" drum spindles as a basis for a disk upgrade. Although at this point I personally wouldn't use 10" drums either, it's so much easier (although more expensive) to swap on the later disk spindles and go BBP. Then you have all stock parts still, can get parts anywhere and have a better wheel selection to boot. But I know some folks want to keep the SBP and original wheels, although that still rules out the Wilwood kit with the hub diameter issue.

 

[Aussie Kel]

You're right, at least for the '72 and down drum ball joints. Both the 9" and 10" drum lower ball joints use 1/2" bolts, the 67-72 KH disk spindle lower ball joints use 9/16".

I must have been thinking 73+, those 10" drums use the same lower ball joints as the 73+ disks and have even larger 5/8" diameter bolts . The also use the larger wheel bearings and the 73+ drum spindles had large upper ball joint tapers as well.



Yup, the 9" drums use smaller outer wheel bearings than the 10" drums did. They also have the "gooseneck" looking design on the spindle. I still wouldn't use 9" drum spindles as a basis for a disk upgrade. Although at this point I personally wouldn't use 10" drums either, it's so much easier (although more expensive) to swap on the later disk spindles and go BBP. Then you have all stock parts still, can get parts anywhere and have a better wheel selection to boot. But I know some folks want to keep the SBP and original wheels, although that still rules out the Wilwood kit with the hub diameter issue.

Hi All, thanks for the input guys but here in Aust we're pretty limited to what is laying around for old Mopars, from what i have discovered anyway. So the Willwood Kit has arrived and I will be using it. They had one sitting on the shelf in a speed shop here in Aust!! it was cheaper than getting one from the US.
I have aftermarket wheels with 3.125 bore already on the car, they used a wheel adaptor plate to go from the 5x4 to 5x4.5, which i wasnt a big fan of. They are 15x7" US custom rims.
I have the 10" drums on the front. The front end has been rebuilt before i bought it so that should be all good.
I will keep you all posted as to how it goes. Cheers