[Mike Simard]

I agree with John Owen about the pulleys. They're mis-aligned and something needs to be spaced. I personally don't believe that the engine was running dry all along and that it caused the water pump pump to contribute towards belts flying off, I would guess that that you overheated only after the belt came off. Anyway, to align the belt, place a straightedge on the crank pulley and note the distance from the edge of the pulley to the belt, keep the straighedge on the crank pulley and swing it around to the accesory pulleys. I suspect you'll see something obvious. Also look for the alternator being square, the crank and water pump will be square but sometimes the alternator winds up in funny positions. Check it by placing the straightedge on the alternator pulley to verify the distance to the crank pulley, if it's different when you hold the straightedge on the alternator versus the crank you can assume that the alternator is crooked.