Thanks for the diagram. It will probably work without damage. However if the 300 lb of brush hits a snag, the line tension can increase significantly vary quickly. An 8K winch has plenty of power to tweak a loader arm, or damage a bucket. I would not do this, or I use a lower powered winch that would not have the strength to bend the loader arms. A solid mount like
@BlueKnife stated is required for a stronger winch. Most likely your fine, with your plan, however the potential of damage is too high for my risk appetite.