Brakes

[gh5168]

I am considering replacing with drum brakes with disk brake kit. I called a a company called Performance and they said that it is possible that the original wheels might not work with the brake kit because of clearance. I have the original 14" wheels. Has any one else converted to disk brakes and used the original rims.I really want to keep the original wheels.
Thanks
Gary

[joe_padavano]

Originally Posted by gh5168

I am considering replacing with drum brakes with disk brake kit. I called a a company called Performance and they said that it is possible that the original wheels might not work with the brake kit because of clearance. I have the original 14" wheels. Has any one else converted to disk brakes and used the original rims.I really want to keep the original wheels.
Thanks
Gary

It depends on the wheels. In the 1960s, GM used 14" wheels that were drum-brake specific and will not clear even the OEM 10.75" rotors. For example, the pre-1970 Super Stock I wheels will not clear disk brakes. The 71-72 SSI wheels were recontoured and will clear the FACTORY disk brakes. All SSII/SSIII wheels will also clear factory disk brakes.

I make the distinction because there are many aftermarket disk brake kits that are slightly different from the factory ones and even the SSII/SSIII wheels will not clear these.

[gh5168]

thanks Joe I do have 1972 442 with the drums on it with the SSII wheels,so I should be ok to replace them?

[joe_padavano]

Originally Posted by gh5168

thanks Joe I do have 1972 442 with the drums on it with the SSII wheels,so I should be ok to replace them?

The SSII wheels will clear the FACTORY disk brakes. No guarantees on aftermarket disk brakes.

[Olds64]

Ask the company you are going to buy the kit from what the measurements on the wheel need to be. Wouldn't measurements like the wheel offset determine whether or not they would clear the brakes?

[joe_padavano]

Originally Posted by Olds64

Ask the company you are going to buy the kit from what the measurements on the wheel need to be. Wouldn't measurements like the wheel offset determine whether or not they would clear the brakes?

Unfortunately, that info alone is not sufficient. Two different wheels with the same diameter and backspacing can have different caliper clearance due to the contour of the rim portion of the wheel. The size and location of the dropped portion of the rim, where the bead of the tire goes so you can force it over the outer diameter, is different on different wheels. The SSII/SSIII wheels are contoured in a what that does not provide much clearance for calipers. They were factory available on disk brake cars, but some aftermarket kits will not clear. Some of the better disk brake kit companies actually provide templates that you can print out and test on the inside of the wheel.

[Olds64]

Hmm... bummer.

[citcapp]

I have been checking into disk brake kits for my 57 and for what its worth both Mike Pemberton (an Oldsmobile guy) and Scarebird Classic Brakes say say you have to use minimum size 15" wheels with correct offsets.

[joe_padavano]

Originally Posted by citcapp

I have been checking into disk brake kits for my 57 and for what its worth both Mike Pemberton (an Oldsmobile guy) and Scarebird Classic Brakes say say you have to use minimum size 15" wheels with correct offsets.

Well, I have several factory disk brake A-body cars with totally stock 14x6 and 14x7 SSII/SSIII wheels on them. Once again for those who didn't hear me before: FACTORY 10.75" disk brakes will clear 14" SSII/SSIII rims. They came this way from Oldsmobile. There are NO guarantees on aftermarket kits.

[GoodOldsGuy]

Originally Posted by joe_padavano

Well, I have several factory disk brake A-body cars with totally stock 14x6 and 14x7 SSII/SSIII wheels on them. Once again for those who didn't hear me before: FACTORY 10.75" disk brakes will clear 14" SSII/SSIII rims. They came this way from Oldsmobile. There are NO guarantees on aftermarket kits.

Joe is correct. My 68 for example has 14X7 steel wheels which were NOT standard. I did this because I converted the front drums to factory disc brakes and they would NOT clear the SSI wheels.

If you are buying from an aftermarket brake company you will absolutely need to determine if they are selling you the 10.75 factory style caliper assemblies or something different. Many companies use larger calipers with different wheel brng/rotor configurations and some even use a spacer. So procede slowly and verify before spending your hard earned bucks.

Regards,

Fred

[joe_padavano]

Originally Posted by GoodOldsGuy

Joe is correct. My 68 for example has 14X7 steel wheels which were NOT standard. I did this because I converted the front drums to factory disc brakes and they would NOT clear the SSI wheels.

Just to clarify, there are two different types of SSI (and similar Chevelle SS) wheels. The 66-69 wheels are drum brake only. The 70-72 wheels have the backside recontoured and do clear disk brakes.

[Jamesbo]

I have found this site helpful to break down the differences in SS wheels.

http://www.oldsmobility.com/superstock.htm#NOTE%205

[gh5168]

thanks everyone for the info. I went to my local auto parts (O'Reilly's) who can get me the factory spec calipers.rotors and booster kit and hoses. I will have to get the spindles from some one else