yes there is a HD cooling one for police cars
8 vanes and a 5/8 shaft larger bearings
it has ribs down the neck,other is like a gatling gun...long tubes down the neck,most times will be a 6 vane
8 vanes non a/c pullys
6 vanes for a/c pullys
both move same x amount of water at idle,8 vane with a/c pully can cause it to cavitate at high rpms(marine engines),ma mopar used 8 vanes on some police cars for the added fan rpms at idle for oil,tranz,PS,rad coolers
they did more idle time/traffic than high speeds like the cruzers
correct size pully help the alt/charging sytems,I have seen cop engines with larger alt pullys before also