Braking vibration

My 79 Lincoln Town Car vibrates in the front end during hard braking and braking from more than 30-35mph. There is no vibration in the rear, during turning or felt in the wheel. Is this wheel bearings, rotors, steering linkage, tire belts slipping or suspension? She has four wheel disc with early version of anti lock on rear. Brake fluid level is good with no leakage. Tires are near new but sat for long time parked in garage.

That’s usually caused from warped rotors.

Take it to a shop so they can check the rotor run-out.

Tester