After reading several posts on exhaust temps I installed a ECT guage and a boost guage.After taking a trip to Cananda from Calif. pulling a 10,000lb 5th wheel I did notice that on most long grades that my ECTs would run anywhere from 1250 to 1500 degs. depending on how hard I pushed the truck (stock 2004.5 with the lly). My question is if the general public did not hace a ECt gage and most do not and there is no mention of exhaust temps that I can find in any of the GM publications, then maybe we should not worry about high the EGT temps. Maybe there is somthing built into the ECM to control how hard these engines a pushed. I might add that even though I was running stock I still had plenty of power to go up the hills as fast as I wanted too.