Below is a quick shot how I've modified my ssc-32 for checking analog voltage input for other than 5v. I removed the chip, bent the analog voltage reference pin out the side a little, and the put the chip back in. then I carefully soldered a wire to the pin and jumpered it back to the board 5v power. Now when I want to use an analog reference voltage value less than 5v, I just unjumper from the board 5v supply, and connect to the desired reference voltage.
Edit: If one decides to solder a wire to the voltage reference pin, it would be easier and probably safer to do it while the chip is still out of the board socket.