Overdriven pulley how much is too much?

GTX JOHN said
Well Gentleman, I have had the opposite effect.
The water goes thru my radiators too fast and does
not have sufficient time to cool as effectively.

I wish we could put that wives tale to rest. This might happen but not for the reason you say. It might be caused by turbulence in the block, preventing heat exchange. There used to be a cooling/ rad website that refuted this claim.

Here is one:

https://www.stewartcomponents.com/tech-tips/tech-tip-3-thermostats-restrictors/