Mate I pulled a 685 with a GUIII 3.0, and it did it well.
I'm in trucks and earthmoving gear, and having lived in the damn things, I kinda "have a feel" for machines, and how they're coping.
I always felt a little concerned about the Patrol. It did well, but never... quite... felt... right... Get a 4.2, or spend the $ on a Cruiser.
Cheers,
Tim