Brake pedal issues after installing power unit

I have a 68 dart which had manual brakes - 4 wheel drum. I installed a power brake booster which has an adjustable rod. The car stops very well now but I have issues with the brake pedal not returning or returning very slowly. Can’t see a return spring anywhere. I reused the original master cylinder. Second issue is the pedal seems high. Any guidance on how to set pedal height ?