How to make a big block hitbox?

Hello everyone!
I made a model for a decorative block, which is twice as tall as a regular block (the standard height on the Y-axis of the block is 16 pixels, while my block has a height on the Y-axis of 32 pixels). I don't quite understand how to make the entire hitbox of the block visible, regardless of which part of it I am new to. If someone knows how to do this then I would be grateful for your help.