You'd have to have the arms of hercules to push on the short stub that sticks out of the transmission housing and expect the clutch to release... correction Superman's arms. You might have changed the geometry of your clutch set-up when you bolted it up to a different engine. There really isn't much movement in a clutch. You're just looking for enough movement to press the release bearing onto the fingers of the pressure plate so that the friction plate slips. Your seven inch travel at the clutch pedal translates down to about a half inch of movement at the throwout bearing contact with the fingers (if that much). If you've done all the bleeding, the next step is to drop the transmission, check the components and measure. Did the new engine come with the clutch assembly or did you switch off the clutch from the previous motor?

1.The pilot bearing could be seized on the end of the trans shaft keeping it turning.
2.The throwout bearing could be damaged/seized
3.The pressure plate fingers could be damaged.
4.The friction plate was installed backwards (ask me how I know it can be done
5.There's not enough travel in the fingers to release the friction plate (See #2, & #3)

yeah, it's some work... You might want to triple check the master. The only way I found mine leaking was fluid was dripping inside the firewall under the dash. I assume when you replaced it, you bench bled it before installation. It doesn't take much air to cripple a clutch.