Did you notice a difference in cooling when you swapped over to the smaller pulley?  Also did you notice a power drain when swapping over from the plastic fan to the 4-blade metal fan?  Does it fit in the standard one-piece cowling and did you need a blade stiffener?  Thanks.  I have a similar setup as yours with the super 2 cool and electric fan in the wheel well however at highway speed I run about 110 degrees C.

Yep - I removed the large pulley either last year or the year before and installed the small pulley which seems just fine, even on the motorway.  I'm using a 4-blade fan, super cool 2-core radiator, new heater core in the heater, small steel pulley, 82°C thermostat, slightly older deep impeller water pump (cast impeller, I usually buy extras for service items, so luckily had a new old-style pump on hand).  I have an electric fan mounted between the radiator and inner wing, just in case it gets warm in traffic.

The only problem with the small pulley that I've faced is that the current and newest range of deep impeller water pumps (EVO series) from MSC don't fit the original small steel pulleys, necessitating the additional purchase of a new alloy pulley.

Has anyone had any experience with using different size water pump pulleys?  With summer here and cooling being a primary concern I found for me the small pulley to be better at cooling vice the large pulley despite everything I have read that states the large pulley prevents cavitation.  Is this only a concern if you are running constant RPMs around 5000?  I hope someone can clear this up.

Thanks,
John