Question about Edelbrock RPM Airgap - thermostat housing leak

What thermostat are you using with that housing? I have the same one but a Chrysler style thermostat does not fit it. I might need to use a chevy style, but those have a smaller O.D. And might fit the Chrysler manifold.

Just a 195* high flow t-stat

i cant remember what brand, or even where I got it