The dual thread port sizes are 3/8” NPT pipe. Can be bushed to ¼” pipe or 1/8” pipe. Kits include 2 gaskets and a pair of long bolts.

A major advantage to TBI equipped cars is improved accuracy for the coolant temp sensor as it samples head coolant temps directly and tends to shorten high idle times lowering RPMs quicker.

A benefit to installing your fan switch using the Dual Port Thermostat Riser saves both time and money. Unless you have an aftermarket aluminum radiator, a bung will probably be needed to be added to the radiator for an electric fan switch. The riser block saves removing the radiator, taking it to a radiator shop, waiting for them to install a new bung for the switch, picking up the radiator and reinstalling it in your car. Then refilling the entire cooling system with antifreeze.

TR6 Installation: Loosen clamp and pull off top radiator hose from the thermostat elbow. Remove the elbow and clean up the surfaces of both the water pump top surface and the thermostat elbow. Holding the DP Thermostat Riser in a vise by the end closest to the threaded holes with padding to protect the aluminum riser surface from the vise jaws. Install the sensors/ switch etc with Teflon tape or thread sealant. Use a gasket sealer on the new gaskets (my favorite is Permatex Right Stuff or any name brand name sealer). Tighten the sensors/switch finger tight plus one half to a ¾ turn. The new riser can be installed facing left or right

(right is most common) as long as the recess for the thermostat is at the top. Drop in the thermostat with spring facing down and a new gasket over it and then reinstall the thermostat elbow with gasket ensuring that the thermostat remains seated in the recess before tightening. Tighten the two bolts and put the top radiator hose back on.

GT6 installation. The GT6 is a single port riser due to clearance with GT6 hoses. The installation is similar to the TR6 install as above. The port of the riser should face the right side of the car, recess for the thermostat up, thermostat spring faces down.
TR2, TR3, TR4 installation of the riser is in the location of the thermostat at the joint of the water outlet. Caution the safest way to install the thermostat is to remove the entire water outlet so the thermostat can remain in the recess by gravity wen holding the assembly upright. Otherwise trying to install the thermostat standing on edge must be done very carefully because if the thermostat slips out of the recess, when tightened there is very high probability that the water outlet to the radiator will crack when tightened.

Electric fan switch note: these switches usually have just one wire connection and provide a ground to energize the fan or fan relay. Too much Teflon tape may prevent the switch from reaching ground so go easy using Teflon tape or use a pipe thread sealant instead.