Don,
I
don't recommend a high-amp alternator.
It's just not necessary to keep up with the fan draw, and they tend to fry the ammeter when the battery is low. If you really want to use one, I can send you a shunt wire so that doesn't happen (but the ammeter will read only about 50% actual).
I can't say anything about the water pump situation except that the Edlebrock works well.
I would use a 180F thermostat with a
small hole .