1250 is max temp you want to run sustained, my truck runs anywhere from 800 to 1000 degrees empty depending on outside temperature and hills, speed etc. If I mash the pedal it will rise to about 1200 degrees when I hit triple digit speeds. Towing a 14500# 5th wheel i run a constant 1000 to 1100, climbing the smokies i can see 1200 after many miles 6% grade plus. PHEW, more than you wanted to know, short answer, I think your temps are totally normal....
