Biggest? well I drive a 4.4L Truck on a regular basis, and Iv driven a Mitsi Fighter, which I think has a 6 or 7L Turbo 6 in it. Big fucken motor any way, with a huge Turbo the size of your head and blowoff valve that made the cab shake.
(good way to scare the rice boys)
Biggest engined car would be a 540i BMW 4.4L V8, and the fastest car would be a replica MK1 Escort Works rally car, with a lot more power than they had in the 60s, followed very closely by a heavily tweaked GTs-T skyline coupe.
Smallest enigined car would be a 998cc Datsun 100a cherry.