Thermostat Housing Torque Spec?

Depends on the gasket, I have a silicone Realgaskets gasket and it only needs 25 inlbs. (And yes they is inch pounds per the gasket maker)

https://realgaskets.com/product/thermostat-housing-gasket/

As for AL thermostat housing in a AL intake, I would look to a modern engine fir the spec