you have two options for the engine, you either go mfi and change parts listed, engine from a rs turbo, loom, tank and fuel pump, dash clocks as these are different on late speck xr3i, exhaust, or you have a rst turbo fiesta and you use the engine and exhaust, but convert your loom to suit the engine manangment, either way is good but bit more technical with fiesta rst, hope this helps