TOPIC:

Rubber expanding freeze plugs are available in many different sizes. They are useful for plugging holes. I have a number of different sizes I bouoght years ago at an auto parts store. The larger ones get used for plugging gas cap holes in tanks when bead-blasting or painting the tanks.

Some of the other smaller sizes (1" and 1.125") are used to plug intake ports when blasting.

You can also make a frame to hold a couple of them and build a carb holding tool.