If it's a Mazda, now would be the time to replace the timing belt, tensioner and idler in addition to the water pump.

Engine family is the same as that used in Mazda B2000 and B2200 trucks. Quite a bit of interchange.

That being said, even though the water pump from a B2000 might bolt on, the impeller could very well be different and not give the flow characteristics you need for a low RPM forktruck engine. Make sure you confirm they are the same.