mate its more likely a 2.9i then.
i have personally never had the engine bolted to a gearbox. i just bought a spare engine incase the one in the p100 dies. i have used a 2.9i flywheel on the p100.
the bloke who i bought it off just told me its a 2.8 flywheel and i nodded and didnt care as i have a good one already