heating problems

[CumminsPower98]

Lately I have noticed my coolant temp running a lot hotter then I'm used to when towing heavy or even empty for that matter. Yesterday coming up the lower steep foothills out of Denver I was clear down in 3rd running about 30 mph pulling an 11,338 lb. 5th wheel and got my temp up to about 225 with only 80 deg. ambient. I have pulled this same hill with similar loads in 5th and gotten up to maybe 220 with higher ambient temps. And other places running in the mid 90s with small hills and some wind it gets up higher then I'm used too. Radiator is 100% clean inside and I have run a bug screen since installing it and also done some hosing and get hardly any bugs out. I have messed with fan clutches and thermostats. I'm starting to think I may have to go to Mopar for a fan clutch though. My last one ran way too much even when cold out and maybe not enough when real hot but not fully sure on that now. I just put on a Napa one and it's like it's not there. I got it up to 200 today just running up a slight grade with the A/C on and 95 deg. ambient and still didn't hear a huge roar like I would expect from that temp. I'm on my way to Fresno with this trailer and stopped home to work on this thing. Now I'm scared I didn't help it and I get to face the Majovi tomorrow. Wish I could afford a Horton.

Could tired injectors cause it to run hotter? I have 381k on the originals and I'm guessing they are tired weather or not that's the problem. Mileage really hasn't changed much if any. I sometimes think I may have lost a small amount of power but that's hard to tell when I drive it all day everyday if it happened slowly.

Any thoughts?