Hey, so I've decided to replace the old corroded water pump in my 55.

For a while I was thinking of maybe going aftermarket and getting a high-flow FlowKooler pump since my 55 has a problem with overheating. But a guy on read on a forum said that a side-effect of a higher then stock pump is "cavitation" that the coolant channels will over time get worn wider and wider until it ruins the engine basically. Is this true? http://www.flowkoolerwaterpumps.com/store/p550/Water-Pump-1635-Ford,-Mercury-Y-Block-%3Cbr%3E%281954-62%29/product_info.html

I've looked for stock pumps that the auto stores sell and the two main brands sold are Murray and MasterPro, which of these two brands would make a better pump in your opinions? The Murray's pump is almost 60 bucks more expensive, but I don't want to let price determine it.

I guess while I'm asking, what temperature rating should I be looking for in a thermostat for a 272 Y-Block V8? I'm wondering if the thermostat I have is rated too high.