So i've just installed an electric water pump using march 22017 kit. I pieced the kit together ? now is what alt pulley # to use. before the electric w/p i was running march 4410(power n amp series) with a smaller 1 11/16" alt pulley to help with charging issues. the 22017 kit lists a larger 2 3/8" pulley. can i continue to run the smaller pulley or would i be overcharging the alt. this would be running a 34" belt.

 

Changing the water pump pulley will not effect the rotational speed of the alternator pulley; that is dependant on crank speed and the diameter of the crank pulley. If you are still using the same crank pulley and alternator pulley, the rotational speed of the alternator will remain the same regardless of the size of the water pump pulley. Look at it like this: you have a single speed bicycle with a idler pulley in the middle of the drive and driven gears. If you change the drive pulley size, both the driven and the idler pulley will either increase in speed (if the drive is larger) or decrease in speed (if the drive is smaller). If we change the size of the idler pulley while keeping the drive and driven a constant, it will require a longer belt/chain and the idler will rotate slower, but the relationship between the drive and driven has not been altered.