MazdaRx7Power

is their anyway to prevent water cavation or whatever its called? does it happen if the water pump housing is rusty and stuff inside or does it happen even if u have a new water pump housing? cause i have the double sleeve alternator pulley but still overheats whenever hailing ***. still havent gotten the main underdrive pulley! will it make a big difference? i know it adds HP but does it make a difference in the over temp of the car? and is it an easy bolt on or do u have to do something special cause i remember somebody mentioning something about the eccentic shaft can be damaged or something like that what u guys think? also can i use the power steering with the main drive pulley or do i have to take it off