The Volvo might could do okay, at least with flat terrian. It ceratinly has more power and torque than a wheezy 84 Le sabre, plus a five speed auto box for better ratios.

But, for longitivity it might not be a good choice. For brakes it'd be fine - it weighs less than a truck, has larger brakes, so the effective total brake to weight ratio would be better. But, since it only weighs about 3750 lbs it'd not be a lot heavier than the towed rig. Plus, the tranny isn't going to be as strong as an Ford EAOD, C6, or GM TH setup. Might could hook it up to Jeff's rig and see how it does.