[Holdon]

I have just been in touch with Willwood as their website said they do a disc brake conversion kit for a 57 Oldsmobile 88, turns out they only do the back and not the front, ridiculous! All I am looking for is a disc rotor that will fit onto the Oldsmobile stub axle, getting a caliper to fit will be the easy part! Does anybody know of any other model with the same size stub axle???

[timothale]

Are the front brake drums removeable, bolted or riveted to the hubs.? I would check out some of the rear rotors from front wheel drive big gm cars of the 80's Scarebird has a lot of disc conversion kits and list one for your olds and had a demo of a 60. very similar.

[joe_padavano]

Originally Posted by Holdon

I have just been in touch with Willwood as their website said they do a disc brake conversion kit for a 57 Oldsmobile 88, turns out they only do the back and not the front, ridiculous! All I am looking for is a disc rotor that will fit onto the Oldsmobile stub axle, getting a caliper to fit will be the easy part! Does anybody know of any other model with the same size stub axle???

All you need is a rotor that fits a 5 x 5" bolt circle, with a center pilot that is close enough that you can machine either the rotor or the hub to fit. As noted, many of the FWD GM large cars in the 1970s and 1980s had rear rotors that should work on your front hubs. Check a late 70s Toronado or Eldorado with rear discs. Here are the dimensions for a 1977 Eldo rear rotor:

[Holdon]

Unfortunatly it is illegal to machine the stub axle as I have already inquired about doing that. Will check out some of those rotors you mentioned anyway though. Thanks.

[joe_padavano]

Originally Posted by Holdon

Unfortunatly it is illegal to machine the stub axle as I have already inquired about doing that. Will check out some of those rotors you mentioned anyway though. Thanks.

The only machining that MIGHT be required is to turn down the non-structural pilot on the face of the flange, the only purpose of the pilot is to center the drum or rotor on the hub. Obviously you don't want to do anything that might weaken the hub. In reality, the hole in the center of the rotor will likely be larger than the pilot on the hub. You are more likely to need a machined ring between the rotor and the hub.