Ford built two prototype 4wd mustangs in 1965. Contracted Ferguson of Jensen Interceptor fame to convert them. So yes, it is something that was done in real life. They also had an early form of ABS. I know this because one has been discovered just down the road from me, and is presently being restored to full working condition. The other was unfortunately crushed. The development notes in the trunk are amazing, even pictures of them running in the alps in snow during testing.
Point is anyone can do anything, with the correct resources. A known engine swap is an LS2 block in an RX7, I installed a 2.0 block with a spoon b16 head in a friends Civic for a laugh. My Father's Corvette C3 has a blueprinted, forged and stroked 500hp 383 in it...
The inability to perform engine swaps in GT is a long running bugbear. Forza is the more accurate tuning sim.