The trucks at my work use ISM's and my old fire departments new used ladder has a red top 400 hp ISM and it's a dog on the hills in Pennsylvania, my station I'm at now has a C12 and it flies up hills.
Probably depends on the governor and tuning. I work at the sanitation department and the ism international 7600 was faster than the kw's with a cat and that was with a boost leak on the ism. After the boost leak was fixed I could be packed out over 60k and it would hit 65 on the on ramp.
Holy crap Love that sound! Can you please get a long driving video from inside the truck? Takeoffs, shifting, jaking (if it has jake). Please do it for me ASAP. Please let me know ASAP.
