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.
If you have a Magnum style Edelbrock manifold like the OP showed in his photo, make sure you are selecting the Magnum style thermostat.
LA is larger in diameter than Magnum.
