they were made a lot longer than that for different applications also the way the law was (is?) written, its illegal to repower a vehicle with a lower tier engine than it came with, however it is legal to repower an older vehicle with a higher tier engine. So if the truck is a 2006, they can put a 2007 engine in it no problem. It's not uncommon to work around that in itself. Trucking companies do it all the time.
my brother works on big trucks and school buses. He's been tasked to bring some of the older buses back online because the new stuff is so much more expensive to maintain/fix in comparison--even after paying him to refurbish the old DT466E's and such. Yes there are newer year model buses with ISB's in them although the majority of them in "his" fleet (114) are International's. Today he put injector o-rings in a DT466E, driver said it was running weird Monday, they checked the oil and it was out. 28 quarts to refill it. Drove it tuesday no problem. This morning it was out of oil again. Took fuel cap off and the 'diesel' is black and running out of the filler neck. Still cheaper (and easier) than replacing a DEF tank assembly.
DT466's have HUEI injectors similar to the old 7.3's. They still have a few 7.3's running too. I need to see if he's got a spare engine for my old truck.....