I am starting a new thread for cooling systems I think it will make it easier to find what people are looking for and not have to wade through pages and pages to find the info.
here is the picture of my Darrin with the 331 Cadillac engine in it with the stock radiator and a 6 blade fan.
I have converted it to 12 volts and put in a pusher electric fan. It works great even in Arizona, I drive this car a lot.
I did learn something when I finished the car and drove it, it did overheat and coolant came out the overflow so I filled it back up and checked it out and drove it again. when I stopped again it came out the overflow again. Not a lot came out so I decided to not refill it again and drove it again. It never overflowed again, it found a level and has been great ever since. might be worth a try if you are experiencing this problem.
Lee