Though it's not exactly the same circumstance, as both engines were turbodiesels, let's remember what happened here in Brazil when Ford started fitting the Cummins ISF2.8 engine to the local version of the F-350.
workaround ideas to discuss among friends: Has Ford gone too far with the engine downsizing in the Brazilian versions of the SuperDuty?
As it replaced the good old Cummins B3.9, an engine with a higher torque at lower RPM, Ford started using a transmission with a wider gear spread and a lower differential ratio in order to keep the performance with the newer engine close to the previous one.