98 tahoe water pump

[Bronko1]

I have a 98 4wd with tow package, used to pull 20' car hauler regularly. My water pump is leaking...does anyone know what the "severe duty" pumps at the parts stores have that is different than the standard pump? Seems that they all have to special order the severe duty, but they have standard duty on the shelf. Any help is appreciated.

 

[Slammed]

I think it's a heavier bearing and different position of the fins inside for better cooling