the mk5/mk5a had the old 1.8 zetec in it with 105/130 outputs. The mk6's had a newer/revised version of the 1.8 zetec in it with 115 (gti/si etc) and ford scrapped the 105/130 engines. If you have the 105 engine then source a 130 engine as it should be more or less a straight swap (dont quote me on it though), as i bet a written off 130 escort/mondeo would be peanuts.