Hi Andy, For cost effectiveness and ease of fitting I would recommend fitting another 1.3. The options your state will physically fit and connect to the gearbox absolutely fine, but it's things like the exhaust and inlet as well as the engine management system that could cause a headache. With the diesel you would have to also replace fuel tanks, pumps and lines and isnt worth the hassle Another 1.3 should be easy to source from EBAY as they were fitted to the Fiesta and the Escort of that era and are regarded as bomb proof (Except the one in your boot!). Do you know what the issue is with your current engine, maybe just a head problem....in which case, a replacement head could be the ultimate, easy fix