dear all friend, i'm going to change my nubira 1997 engine, i have some choices: 1- buying a nubira engine : 1600 - 1800 cc 2- buying a nubira engine : 2000cc 3- buying another motor brand ( Opel ), but i'm note sure what type or model will be fit to the nubira, the work shop told me about Opel Omeg...