there was a guy on fiestaturbo.com who done the same type of conversion to a mk3 he used the ford 2.3 duratec which is the same lump basically, he changed the pistons though and had to change a few pulleys and what not to make it fit. his user name is jimmyesh this is his build thread http://www.fiestaturbo.com/forums/mo...hilit=jimmyesh
have a read i'm sure you will find some useful info even though its not a st you can get the idea of what is involved hope this helps a bit, good luck with the project if you decide to go ahead with it. Obviously there will be complications but thats what modifying is all about you live and learn