There are some good suggestions here and I have designed systems for 502s in several applications and will admit, they are not easy motors to cool due to the inherent smaller coolant passages and siamiese cylinder design. They are a marine block afterall.
Synthetic oil might make some difference, but you want to run that anyway. Great suggestion.
Your readings of 200+ is not that bad at all. Like one poster mentioned, as long as your are keeping coolant in, you are fine and the suggestion of a higher pressure cap is great.
The suggestion of cutting back on antifreeze is an excellent one! Antifreeze degrades the absorbtion of heat. The more water the better. You can run straight water if you use a anticorrosion additive and have plenty of pressure to boot.
Do not use reducers. FLOW IS KING, FLOW IS KING, FLOW IS KING...kinda get the idea. Reducers will impede flow and reduce the efficiency of the system as their name suggests. Use a thermostat...a 195 is perfect and for Pete's sake do not run it without anything. That is a whole other science lesson in flow.
YOur aluminum radiator is a great idea and aluminum is the best media for cooling. Is that a 1", 1.25" model? Bigger tubes have more area for cooling and flow better. Remember the flow thing?
The water pump on the 502s are minimal at best. I would change it. DO NOT USE AN ELECTRIC PUMP EITHER, they are STILL not for the street. The typical high performance water pump will easily triple the flow output of the best electric ones! Check all the charts out...you will see what I mean. Remember the flow thing?
The Black Magic fan is not what it's cracked up to be in my opinion. I would change it last for more airflow. I have tested the fan and the suggestion of going to either a Windstar twin fan unit or the Mark VIII is an EXCELLENT choice.
You can run overdrive pulleys but are stuck with the serp system already in place (there is a system called ConceptOne that overdrives the waterpump and alternator that are made especially for this engine). This is an increase in coolant flow as well. Remember the flow thing?
Lastly, but not leastly.....go to my cooling forum at www.inccn.net/techforum.htm
for other ideas. I have alot of happy and cool Florida customers.
Engineering and Marketing Technologies
Techical forum/links at www.inccn.net/techforum.htm
[This message has been edited by HOTRODSRJ (edited 05-07-2002).]