A good grounding scheme will have the negative battery cable bolted to the engine block. The largest current draw in your Bronco, besides possibly a winch, is the starter. The starter grounds internally to the engine block, so the main ground tie-point should be the block.
From the block, run grounds to the body and to the frame. I have a small braided ground strap (from the Help section of the local auto parts store) run from the rear of the intake manifold to the firewall. I also have a larger braided strap run from the same bolt where my battery cable mounts, to the frame.