Upgrading A C3 Corvette Cooling System - Cool It To Use It

10 Our Vette had been run with plain water in the cooling system, and we were worried about rust and gunk from the water jacket fouling the new radiator. While it was apart, the thermostat and water pump were removed, and the water jackets were thoroughly flushed until all the loose rust and scale were cleaned. We also flushed the heater core circuit and then installed a new thermostat-cheap insurance.

11 Now was also the right time to replace the waterpump. We just used a rebuilt stocker. With the electric fans replacing the original mechanical unit, the pulley is simply bolted directly to the water pump's drive flange.

12 We really like the Spal electronic fan control that came with our DeWitts system. Rather than a simple thermostat/on-off, this system varies the fan capacity based on temperature. The wiring kit is complete and comes with most of the terminal connections already made.

13 Getting the radiator support in position started the DeWitts' install. Rather than trying to wrangle the bulky assembly with the radiator at once, this is the easier way to go, especially for a one-man installation. The lower two bolts were started a few threads for now, and then the support was tilted forward, as when the old radiator was removed.

14 With the core support tilted and tied forward, the radiator is more upright, making it much easier to slip the radiator down on its saddle mounts when working solo. The original saddles and top clamps fit the DeWitts radiator perfectly. It's a good idea to replace the rubber at these mounts when installing the new radiator.

15 Once the radiator was secured, the core support was tilted into proper alignment, and the bolts along the fender apron were installed. To ensure the fasteners line up, get all the bolts just started before cinching any of them down. Once they are all in place, they can be tightened.

16 We took the time to clean, detail, and paint the A/C condenser. It slips down over grommets at the bottom, and bolts up top with the outer fasteners from the radiator's upper mounting brackets.

17 The flat on the firewall just adjacent to the wiper motor seemed to be the perfect mounting point for the Spal control box. This position allows easy access to the programming buttons, and provides full view of the monitoring LEDs. The relay for the secondary fan fit right below. You can also mount the controller in a hidden position to retain an OEM appearance.

18 DeWitts' Direct-Fit radiator and dual-fan setup looks like it was born in our Corvette's engine bay. The system toys with anything our small-block can throw at it and has the reserve heat-rejection capacity to handle future engine mods with ease.