Well, tell me then, if you were going to judge this as the absolute factor for lifting your foot, I would want the sum of the whole, not sum of the hole. The heat in the back of one manifold is not the sum of the temp before or aft. Have an injector fail on the right bank and see how long it takes for you to catch it. I have run them on mine at different points and multiple gauges. It may first appear to be more accurate until you relize the thermocouple is right outside one port on one bank. Banks used to say before also, so did Cat, Cummins and Detroit diesel.