That's a 1-barrel choke thermostat you show in your pic—not compatible with the 2bbl carburetor (nor with that '73-up exhaust manifold also shown in your pic, for that matter).
Go get a № 1232
electric choke kit. It will attach to your exhaust manifold at the bottom end just fine. It would attach just fine your Carter 2bbl carburetor at the top end, except you have a V8 BBD rather than a Slant-6 BBD. The difference (the one that matters at the moment, anyway) is the configuration of the choke lever. You will have to either make a new choke pushrod or make an adapter piece like
this.
