What's the hole in the intake for....collecting antifreeze

X -1, I dislike gear-clamps more.
My favorites are the flat-band spring-clamps. They are self adjusting as the rubber gets soft and squeezes out. And they are easy on the hoses, even though they put a lot of pressure down. Plus they are reusable like maybe forever.
At7psi, I have used cereal-box paper for a gasket there. No it doesn't last forever, but I think it went a few weeks for me.
Here in the Northland our summers are short and not very hot, so we can get away with some/lotsa stuff alrighty.