M923 5ton horsepower gain

The fire dept I belong to just got a 923 with the nhc 250 engine . It’s out forestry truck. We have a 600 gal tank on the back and some hand tools. We only use the truck prob 5-6 times a year and we don’t go far with it . Was wondering what’s the quick and easiest way to gain a little my hp with this engine ? If I need to install a egr temp gauge I can do so to monitor the temp . Truck goes fine straight down the road but the hills it down shifts and goes pretty slow. We have changed all filters on truck

I see you've only heard crickets since this morning. Have you tried the search function focused towards this forum and the 5 ton modifications forum? Your question has been asked and answered many, many times. There's a hell-a-va lot of smart folks on this site who have provided good answers WITH great explanations as to why. I also have a M923. It's a dog too. I have to downshift as well. To that end, when you find the (small) mods you can perform on that engine, perhaps you might notice a difference.

Good luck!

Al Jones
Brookings, SD

A few guys have added turbos to their 923s as well and have pretty detailed write ups about them in the sections that @jonesal mentioned above