Choke thermostat problem

No, it's easy to check the spring assembly from underneath and sadly, the spring housing is definitely blank... No index mark.

Before trying something else, I plan to rise the carb to the correct height.
First, by piling up the three thin gaskets and then by installing the NOS high gasket I ordered on Ebay (thanks to Townsend who gave me the link) as soon as I get it here.
Mopar gasket.jpg