So I’ve installed the heat sinks on the stepper controls a little different than what some people may have expected. I mounted them upright. The reasoning for this is that the heat sinks are pretty big for the board, I didn’t want to risk having the heat sink short out the components on the board by touching them. With the setup I have now, it should pull enough heat away from the chip, and you can see from the picture the heat sink is no where near the pin or resistors on the surface of the board.
Heat Sink Install
Heat Sink up close