I have used alignment tool to align engine. Takes 3 fingers to remove tool, witness marks good. Go to install drive and it slides in to about 7/8 of inch to mate with bell housing then stops. Shifters are aligned, oring is in position, just will not go in. Tried raising and lowering engine, alignment tool will go in easily. Still the same issue. Is it alignment issue with Gimbal bearing? Boat not level? What am I missing on alignment?