Did some more thinking...
The fan clutch maybe something to look at. Before there were 2 belts around the fan. Now due to adding the AC Compressor I have only one. Maybe the big fan clutch is putting too much resistance on the belt.
What is the best fan clutch to replace mine. Is there a way to test a fan clutch?
There are not great tests for the fan clutch but a few that can be done. First is easy - check for slop in the bearings. Another, is when cold and engine off, it should spin without too much resistance after a few turns to loosen it up.
As far as clutches, the "loosest" was the MP viscous kit which does not seem to be available any more.
A "heavy duty" clutch is made for the big 7 blade fan. It will tend to "lock up" more, especially with a lighter fan. I am thinking the "heavy duty" clutch probably wants 2 belts.
I have recently used a Bouchillon thermal clutch with their 6 blade fan to to replace the MP unit and it works well with my "single belt" setup for the fan.
