Pyrometer and diesel trucks

Getting the temp info is a smart move. I have a 2006 CTD like you and have the older EDGE/Attitude computer with EGT. I use it to monitor EGT, boost, tranny temp, and load percentage. EGT temp has a warning alarm at 1350 degrees, and tranny temp warning at 230. You will probably reach these temps while going up some of the steep parts of the WA Cascades depending on how you drive. These temps are about the max you want to be seeing, but the truck doesn't go into limp mode on the tranny until 265ish and not sure how high you can go on EGT's. With the 48RE 4-speed auto, just use the O/D Lock-out and you can climb the hills in 3rd as fast as you want. The gauges tell if you are pushing it too much (100% on the Load Percentage), or if there is still room to go faster (90% on the Load Percentage).

Going down the mountains is another story --- does the trailer have brakes? Surge or electric? An exhaust brake is awesome but you have to be carful to not overheat the surge brakes on the downhill.