Retired from GM
It’s not unusual in the Medium Duty Truck segment, which is where the F250/350 reside. In fact, it is not unusual to have low power / high power variants of the same displacement in that segment. This is really common with diesels in this segment, but not uncommon with gas engines. GM, for example, had high and low power 6.0L gas and high and low power 6.6L diesel on the same trucks for years. Half liter displacement difference is no big deal for this market.It makes more sense to keep the 4.22 bore and shorten the stroke for more rpms. Otherwise, I can't see a reason for two engines with nearly the same displacement. But, I'm one of those guys who used to hop up GMC 6 bangers when everyone else was doing SBCs, so don't listen to me!