I used to run one like this years ago on a Duster I took to the track a lot.
The pump attached to the heater coil line circulates the coolant through the block but not through the radiator. You need to add a small cooling radiator to the line and place it in front of the main radiator. Then with an electric fan pushing air through both the supplemental radiator and the main Radiator, you are cooling both the engine and the remaining volume of coolant in the radiator. You don’t need to bypass the thermostat since the new cooling loop is already bypassing it.
You can use a supplemental radiator like this one..
B&M SuperCooler Oil Coolers 70274
