I have skidded many logs with JD 420, B414D, 434, 454 and 684. My advice is to find a used 3pt skidding winch. The 3pt skidding winch will prevent the tractor from flipping over backwards as the bottom of the winch will hit the ground preventing tractor from going over backwards. With the cable on the winch, you can pull logs out of difficult spots with tractor parked with brakes locked and PTO running. Also always skid logs with the top end (small end) of log hitched to the tractor.
Be very careful as cedar tends to grove in low and uneven ground.