If you are doing a conversion, the the pushrod length is probably out of whack. Can you get the car into gear if you let the clutch up about 1/2 to 1 inch off the floorboard? If so the pushrod is adjusted too long. Check for pedal free play before getting tight. If the pedal has no free play, it is partially engaged when the pedal is out and can cause some major disc wear issues. Adjust the pushrod so that the pedal has about 1/2 inch of free play before getting firm. If you get this adjustment correct and the hydro system is free of air, it should slide right int gear.
