Contour Enthusiasts Group Archives Forums General General Difference between England and American Zetec??

I was wondering if there is any difference in Zetec heads from England and the Zetec heads from the States? I have about 20 Zetec heads at work that my company told me to sell. They are from a company called Wealdstone Engineering over in England. They are the biggest Ford Reman in England. I have all of these heads sitting here that I need to get rid of. SO is there a difference between the american zetec head and the england zetec head?