You have to go back to ancient technology that I get to work on. We have probes in the aft section of the engine that you hook the jet cal up to, to make sure the gauges are calibrated. It cooks them to a known good temp and you bounce that off the egt gauge to figure out if you have an engine running hot, or just a gauge out of cal. We didn't have probes as such on the B-1B, so it is likely you have something completely different on the CFM's. I'm kickin' it old school!!
