To answer your question . The cam is not ground properly for length. Replacing it is the only correct fix. Don't listen to some of these quick fixes from others. Any part that drags and creates friction is a bad thing in any motor. Sound like the rear of the cam is dragging on the rear expansion plug. This plug has a step that it seats on in the block and only goes in to a set depth. So not putting it in as far is not the solution. Catching this was a good discovery on your part. Some would just slap it together and let it wear in..
Correct off center lobe location is essential for lifter rotation as the cam rolls. This is what prevents wear . If the lobes would be center the lifters would wear the cam out immediately. Good find. Steve