79 toy is correct, forget about performance gallons per minute etc. the "corvette" water pump is a application specific pump. And you can bet if you go with the sbc "short" water pump, your water pump pully will not fit, and your belt alingment will be a tad off. The corvette pump is not more expensive (relativly speaking) a standard new in the box "rebuilt" is about 20 bucks, so they are not corvette price gouging you, I personaly feel the long term cooling and reliability of the water pump is significant enough to spend the extra money. When you run it hard, flow rate does matter. I can't justify 300.00+ for electric water pumps "race" pumps, but for about a 100 bucks, I feel the few extra bucks to protect my motor with a stewart stage 3 pump is worth it. Look at it like insurance, a hundred bucks is nothing to cool a 5k motor. or an original irreplaceable idem. just my opinion.