[Steeveedee]

Depends on your budget. You may be able to pick up a hydraboost system cheap at a wrecking yard, but most of them use a later model master cylinder. You could switch to a manual brake master cylinder, which is even available for disc brakes, and just ignore the low vacuum signal altogether. The pedal effort is about like manual drum brakes. Even my wife can stop our van with hydraboost, if the engine quits.