brakes: Master cylinder help needed

[bmxmon]

I just started bleeding my brakes for the first time, since i upgraded to a dual master cylinder. My car is a 65 mustang, and I put in a 67 mustang dual master cylinder, along with the push rod. I was bleeding the brakes, and there was probably about 3-4 inches of free play before it started to get hard for the last 1-2 inches. (brake pedal movement) Then, it just stopped going up at all, so the brake pedal sits really low. I tried pulling up on the brake pedal pretty hard, and I couldnt get it to budge. Im guessing I pushed the piston in the master too far. Is there any easy way to get it to come back?? Can i adjust the stop for the brake pedal under the dash, and if so, how far do i want it to go? Thanks for any help.