Disc Brake Conversion Recommendation

I think a lot of those kits use most the same parts. the rotors, calipers, mounts and probably spindles. I know a lot of guys use the corvette non power master for disc and I have seen them on disc front with drum rears. My 55 has non power disc front with drum rears and corvette type master, not sure which proportioning valve.

 

It is some caliper bracket they say they are waiting on.

 

I got all my disc brake conversion parts finally from Right Stuff, but I haven’t done the conversion yet.

I just watched this video, which I thought was quite good.



At the very end, he shows that on a 1970 Malibu originally with 14 inch drum brake wheels, the caliper rubs up against the wheel, so the only way a 14 inch wheel is going to fit with the 14 inch disc brakes is if you have 14 inch disc brake wheels not 14 inch drum brake wheels, which I don’t think were available on the 68 GS 400. Or you have to go to 15 inch drum brake wheels and use with the 14 inch disc brake conversion kit.

I didn’t fully understand this point before, but I think this may be a general issue with 14 inch drum brake wheels.

I think I may need to get 15 inch wheels before doing the front disc brake conversion.

 

Thanks. I talked to Right Stuff again and I forgot that this kit is specifically made for 14” drum brake wheels, so they may fit. Most of the 14” kits are for 14” disc brake wheels though.

If they don’t fit, I will be getting 15” wheels likely.

Thank you for the chart. That is very helpful.

 

Baer brakes manufactured a front disk brake kit for a-body cars that worked with drum brake wheels.

 

I put the 1969 single cylinder Front Disc setup from a 442 onto my 1968 GS and it definitely fits well with the 14" rally wheels. FYI.

 

Reporting back. I finally got my disc brake conversion kit with 11” power booster on my 1968 GS 400 convertible with 14” rallye wheels.

These RightStuff kits worked well for me and fit.

https://rpui.com/-Brake-System-1967...ter-Master-Cylinder-Combination-Kit-G10030971

https://rpui.com/-Brake-System-64-7...Conversion-for-Factory-14-Wheel-Setup-AFXWK14

 

That's cool. It doesn't include spindles and I guess it fits on the Drum brake spindles? I remember having to replace mine when I put 1969 442 disks.

 

The AFXWK14 kit bolted onto the stock drum brake spindles.

 

The C5 kit with the C5 hub bearing spindles?

"6474SWBK-STC5R"
https://www.classicperform.com/C5-Spindles/C5-Spindles.htm#:~:text=.-,6474SWBK-STC5R,-7081SWBK-SC5R

 

Looks like Wildwood has a bolt on conversion kit now for GM A-bodies with 14 inch factory drum brake wheels.

I’m not sure it will 100% fit without modification but I think it will. They have 3 different kits. Anyone try these yet? I didn’t come across these earlier in year when selecting mine. Maybe they are new?

Classic Series:

https://www.wilwood.com/BrakeKits/B...year=1968&make=Buick&model=GS+400&option=Base

Forged Dynalite Pro Series:

https://www.wilwood.com/BrakeKits/B...year=1968&make=Buick&model=GS+400&option=Base

Dynapro Dust-Boot Pro Series:

https://www.wilwood.com/BrakeKits/B...year=1968&make=Buick&model=GS+400&option=Base