I will keep you updated. I am waiting for a 1978 Malibu manual brake master cylinder with a 7/8" bore to install and test.
Because the manual brake master cylinder from a g-body has a shallow cup to retain the pushrod (actually it is just a dimple), the pushrod is not held in by anything. You need a retention cup (or something other devise) to make sure it doesn't fall out the back of the master cylinder. If the pushrod does come away from the master cylinder piston, the retention cup keeps it in line with the "dimple".
Pushrod Fall Out the Back = No Brakes = Injury or Death
Last edited by malibudave78; 01/03/12 05:19 PM.