I want to convert to discs...

May 1, 2010 | By Richard Prince


I’m restoring a 1968 Oldsmobile 442 with drum brakes and no power assist, and I would like to put disc brakes from a newer 442 or Cutlass on it.

Can I use just the spindles with the disc brakes or do I need the A-arms too? Will the power booster for the discs need more than a vacuum line to the intake? Any other ideas would be helpful.


You won’t need to change the control arms in order to use a compatible newer GM disc brake system.

A disc setup from a 1968-72 Chevelle is probably the easiest to find, but any GM A-body donor will do the trick.

You will, however, have to adapt your original Olds steering arms to work with the later disc brake spindles by enlarging the mounting holes.

If you gather together used parts, make sure the rotors are thick enough and straight enough to be machined. It is always advisable to rebuild used calipers even if they look good to the naked eye. Wheel bearings should be cleaned, carefully inspected, replaced if necessary, and repacked with grease if they are OK. Do not reuse old brake hoses or old brake pads.

In the end, it may be worth the time savings to simply buy a complete kit from any of the many vendors that sell them. The power booster will need a manifold vacuum source and you’ll need a master cylinder specifically configured for a front disc/rear drum system.