[G.M.]

I have posted maybe a 100 times about the use of modern thermostats in the hot summer causing the engine to run hot even with 8 .125 holes drilled in the flange to try to increase flow. Thermostats with small flow openings are like putting washers in the hose as recommended by lots of people for 60 or more years. The water was going out the over flow and the washers, the same as small thermostats slowed the flow, less flow eased up on the volume of water going into the top tank.
Less water into the top tank allowed less to flow out the over flow. This works in cooler weather but causes the engine to run hot in hot weather BECAUSE
less water is flowing through the radiator. With the 4 lb pressure cap or 3 lb valve
and either NO thermostats or Bob Shewmans full flow stats much more water is FORCED through the radiator. As I said a hundred times better cooling is achieved with more water in the system (filled up in the neck), more water flow by using pumps that deliver more water. Like the promotion or not there are NO PUMPS that come within 25 gallons in 5 minutes of what Skips pump produce. A shroud and a QUALITY 6 bladed fan also help. Make anyone of these improvements and you get some improvement, do all of them and it won't go over 180 at fast idle or road speeds in 100 degree temperatures. Henry I think you must be so engrossed in your ramblings that you don't read what others write or maybe you just don't understand. I would say it's both. G.M.