Got new car!!!! what the ????

Just bought 72 duster with a 4 speed and 8 3/4 posi rear.
Just a 318 but built to rev.
Great to drive.

push the clutch all the way to the floor and bam!!! it dont come back?
push it just far enough to work safty start and it is fine, but any further and bam, got to pull it back.
It is like it is camming over.
Whats is going on???