Meter

Sounds like you are letting the Alison do the driving…put it in D and push the right pedal. A Alison 4000 will lug a 600 ISX… will not down shift until below 1400 rpms which is fine in hilly terrain BUT not when climbing a mountain. You need to manually downshift and keep the rpms above 1800 when climbing for more than 2 minutes. Doing this should keep the temp below 200 and the exhaust temp well below 1200…if you’ll downshift you do not need an exhaust temp gauge. I’m surprised you do not have a boost pressure gauge on the dash.