Or you can modify the stock motor, or purchase a different motor and modify it in all the same exact ways. Every motor is modifiable. I'm not expecting drivetrain swaps or motorswaps for that matter, but still, I'm not seeing how you think it's that different, really.
It all seems to revolve around the same idea. You'd be able to purchase different intakes, fuel systems, exhaust systems, cams, bore out the head, valves, induction types, cooling systems and so on in both games, and it's not to far off to assume that they'll have different levels of each part. If that's the case, It seems like a similar system to how FM6 has, albeit, with a few more additions like the ECU and different blocks and what not.
I'm really interested to know what it means about durability up in those quotes, as that would be an interesting aspect to have in the game.