not at all, its really not that hard to do, if u run it on bike carbs, u need an ESC control unit (at very least) off a mk3 fiesta 1,1 or escort 1.4/6, its 3 wires into the original dizzy plug wires, then its plug and play into the engine. theres soooooooo much information on the net for the conversion as its soo popular, like i said, ask on xrtwo.
the 1600 xflow really isnt worth while doing tbh, cvh and zetec are easier and get more power out of them for less money, plus easily replaced.
BTW, u CANT use a rwd xflow block unless u make up mounts, u need a 771m and NOT a 711m block if your going xflow