Sometimes Older is Better

I had to run one of those on my 440 magnum Roadrunner because before I put it on I pulled the damn pump shaft right out of it's housing and bearings and two weekends in a row I had to put another fan, shroud, radiator and water pump on it.
No problems after that and it cooled fine.
Dang, what were you running that pulled shafts out? A stock fan combine with high RPM's?