brake problem

Hi, having a problem finding a brake master cylinder for my 89 olds t/s.It abs system on the car.Dealer said gm doesnt make anymore and cant find at any parts store.I guess the master cylinder and brake booster(which is a electric motor) comes together. Ive also been checking salvage yards on line no one seems to have it. Thanks

Rockauto's catalogue shows 5 different master cylinders for your car.

www.rockauto.com