Classic Radiator Question Carb vs. Injector

Well, I just might have made quite an expensive mistake... Allisport has the new radiator ready, which great. Obviously, I ordered the carb version with a single breather.

Well, something bugged me. So I checked. And while I clearly have carburators installed, I do have one pipe from the radiator to the coolant overflow tank (great), and a second one from the radiator to the inlet manifold... That's obviously not great...

Is that normal? Can I just plug the hole in the inlet manifold? If needed, can I just put a Y-connector in the pipe between the radiator and tank to connect the manifold?

And why would I have a injection manifold on a carburated engine to begin with?

Damn, that'll teach me, hopefully...

Nevermind, just had a back and forth with Allisport. I do need the second connection, no idea if some later carb engines had manifolds with a radiator connection or if it some aftermarket manifold. Either way, Allisport will add the second connector, better to add something than the other way round, and all is good!