Weird thing in the MotoRad 206-180 Box

I've just found that using the same material t-stat housing as the intake manifold keeps it from leaking. I check the bolt threading depth and use a regular paper gasket with light film of gray RTV on both sides. Also coat the bolt threads with liquid PTFE. Lightly thread in the bolts just until the RTV starts to squeeze out then leave it overnight. Next day, torque the bolts down and reassemble. My D200 and Duster both have 360s with LA Edelbrock intake manifolds and both have aluminum replacement t-stat housings from the parts store. I don't like how they don't have the rib on top for the upper rad hose to "grab" onto but I've never had an issue with the upper hose blowing off and I have high-flow water pumps on both engines.

The housing on my D200 does weep from time to time but that intake manifold (Eddy Performer) is very old and beat-up, had to chase a lot of threads and for some reason the sealing surface around the thermostat is not as wide as others I've had. I don't really care anyway as it's not a show vehicle, I use it for towing and hauling.