How much power with a manual water pump?

I ran my 440 with the stock Chrysler pump for years with no problems, it was on the housing when I got it so has to be good right? Now the last time I refreshed the motor I put a new Eldelbrock on it.
I ran the car with the Moroso pump drive one year but didn't care for it.
I like the reliability of the crank driven water pump.

I'll add that this 440 is 645 hp 620 tq.