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Outside of brakes that literally barely worked, the next biggest problem with my car (when I bought it) was that if I took it for more than a 20 minute drive the cooling system would boil over when I got home and turned the car off. I decided the best approach was switching from the stock solid blade fan to an electric fan, and add an aluminum radiator. I started with a 16" SPAL electric fan, a Vintage Air fan relay and adjustable thermostatic switch (that screws into the radiator in place of the petcock), and a new Edelbrock aluminum water pump.

When adding an electric fan you have to be real careful about the depth of the fan. I did some investigation and found that the SPAL 2360 CFM fan could pull the most air and was thin enough to work in my setup (or so I thought). Most high flowing 16" fans are much to deep to work with stock radiators. When I first installed the fan it barely touched the nose of the water pump. I had to take the pump to a machine shop and have the nose shortened a little to buy a little more clearance. Figure 1 shows the setup after having the nose shortened. I ran it this way for quite a while, but it was a little close for comfort. A good cooling system flush, electric fan, and new high flow water pump made all the difference in the world. I could dial in the temperature at 160 degrees and the new setup could hold it there even in the summer months in Houston, TX. The bonus was there was a noticable difference in the seat-of-the-pants dyno. My G-Tech, which generally seemed pretty accurate, showed close to a 30hp gain at the wheels. I find it hard to believe it was that much, but I can guarantee going from a non-flex fan to having no fan is huge. If you are running that type of setup and want more power this is the cheapest horsepower you can buy.

The last step in my upgrade was to add a Northern aluminum radiator (you can see it in Figure 2). I sourced one of these from Laurel Mountain Mustangs for under $300. I don't think there is still a cheaper aluminum radiator for a 65-66 that is a direct replacement for the stock one. This radiator was considerably thinner than the stock 3-row that I took out (basically 1" thinner). This gave me the clearance that I wanted, and opened up other possibilities for additional electric fans (although the SPAL one I have is perfect). As you can see from Figure 3, the SPAL (and probably most other 16" fans) fit the Northern radiator perfectly. I got the SPAL mounting clips to hold it on instead of the push through plastic holders (as I thought these would bend the fins on the radiator. I cut the mounting clips to fit, and used some 2" fan shroud brackets to bolt the fan to (as show in Figure 4).

Project Pictures