as above, easier to drop 1.8t into 4mo shell..
to fit 4mo to 1.8t,
you will need :
boot floor pan from 4mo welded in,
4mo fuel tank
4mo exhaust
4mo running gear (prop shaft, rear diff, gearbox, drive shafts, rear arms, rear subframe... the list goes on)
all in all, just not worth it.