The FIAT engine as used by Morgan was not fitted to any mainstream FIAT car sold in the UK. Plenty in USA I understand and spares allegedly easy over there.
The M16 Rover suffered head gasket failure on a regular (30k+ miles if that is regular) basis. The T16 seems to have that sorted, but a check of the Rover forums is advisable. Note, the major problems with K series engines is a different matter...
