Need Help Troubleshooting Brake Troubles

Hi All. I just replaced my Master Cylinder and Brake Booster in my 1973 Plymouth Duster. Everything seemed to go smoothly but I now when I tap on the brakes they compress to the floor immediately which causes the car to brake hard. I have to use my foot to lift the brake pedal back up so that I can continue to drive. Needless to say I'm not currently driving it anywhere... It's gotten me stumped.. I've been looking for info online about this happening to someone else but I'm not finding anything... Any ideas or suggestions?