Was the bolt that connects the fork which holds the throwout bearing to the shaft that the clutch cable torqued correctly? (or maybe it worked loose on its own?)
How much freeplay does the clutch cable have when your foot is off the clutch pedal? (measured at the transmission connection it should be 1 or 2mm)
Assuming you didn't swap the tranny also,
Is the flywheel thinner than the one you had on your previous engine?
(A thinner flywheel would move the pressure plate away from the throw out bearing >> meaning you couldn't fully disengage the clutch)
_or_
if you had the flywheel machined (the clutch surface) and they didn't keep the step distance between the clutch surface and the pressure plate mounting surface to spec, you could have trouble disengaging the clutch fully.
-if the step is too small, you cannot disengage the clutch fully because you've reached the limit of the pressure plate release before the clutch is fully disengaged
-if it's too big, you won't get full wear out your clutch plate
so much fun. (ugh)