When you fit the cvh head onto the zetec block there are oil galleries that don't line up therefor need to be blanked off with brass blanking plugs, the oil return needs to be plummed in above the oil level, as the zetec(except focus rs) was designed as an N/A, check oil pump aswell as these are a big zetec flaw, also get someone with a burrette to check the volume of the bores so at least you will know what your compression ratio is as ideally you need around 8.5:1 for it to run and last