Convert outside temp gauge to intake temp?

I was curious on converting my outside temp gauge to read my intake temp instead. I have gathered some great info on the probe, but my concern is the head unit. From looking through diagnostic threads on the head unit, the head unit may only allow a reading of up to 136 degrees F or 58 degrees C. Can anyone confirm this? If the head unit cuts off at this temperature, I may choose not to try this. Thank you!