hi there I have just joined the site I have a quantum saloon kit car which I want to turbo at the moment it has a standard fiesta xr2 engine box ect but what im wondering is is there much diffrence from an xr2 bottom end to a rst fiesta or escort if not is it possible to use he top end loom every thing and keep the xr2 bottom its only done a genuine 34.000

any help welcomed thanks.
steven.