Hi, I may be late to the party, but this is a topic that is of great interest to me. I have a 1993 7.3 idd N/A with a hypermax pulse turbo setup, e4od, 4wd dually(I did the dually coversion) crew cab XL truck (no intercooler, intake is through the wiper cowl). I make 8 to 9 psi of boost. I run 235 85r16 tires. I am seeing some heating trends that I don't like in my truck as well. I tow a 8250 dry(add a generator and all the camping stuff to make whatever is reasonable here for total weight) 5th wheel, with a full cab of family. Before the turbo truck was slow as can be on some hills but temp gauge never moved from the low side of normal. I now see the temp gauge move right from the middle of the normal to the "l", and then it can hang out there near the "a" and "l" when I am doing 65 with it. I was a little (less than 1/2 gallon)low on coolant and that helped some, but I still don't like to see it up there plus it's hot in the cab. My EGTs in that condition are 11 to 1150 degrees and I'm in 3rd gear, with a stock pump slightly advanced and turned up supposedly 2 flats. When running like this it gets real hot in the cab which is not comfortable. I had to remove the firewall rubber and insulation and replaced it with thin fiberglass/aluminum reflective mat(it's not enough). If your coolant is old, flush the system first and foremost. I too am thinking of ways to get more air past the firewall faster, in hopes that there ends up being less heat to shed at the radiator. I was told that the transmission could be equally to blame as the engine for my Temps. I do have a stock cooler for now, but was going to try an aluminum transmission pan next. I also seem to see that based on injection timing and amount, more diesel fuel earlier will let the engine run cooler(as long as egts aren't going past safe limits). It also seems plausible that the intercooler could be blocking some of the airflow for the radiator. Do they make an aluminum oil pan for these engines? I should mention I have been running some +8 cetane improver and my engine loves it, I cannot believe the difference. I have heard about a aluminum radiator upgrade that has more cores but fits in the same spot... I am sure that the 3.55s are causing some of these "threshold issues" with heat that we are talking about, but.... if we didn't see this problem at the weights we are talking about towing now, we would at a higher towing capacity anyhow. I love tinkering with this truck and trying to get it to do more, it's fun, and I couldn't afford to mod the new stuff anyway, I don't have an uncle Elon. Has anyone tried taking off the front bumper? It would seem that there is air to be brought in if that wasn't in the way... or are there "more open" bumpers that could be used? Taking it off for a short trip could be a good way to see if there is anything there. I am interested to hear what you or anyone else might do to help this situation out. I heard the cowl induction hood suggested and it would seem that you need the air brought in more to the front to have any meaningful impact... like adding a super duty hood from 2000 and leaving the middle portion open(I know it doesn't actually fit, but as a concept...)