when my 4d55 head blew, I ordered a bare 4d56 head, fitted all the parts off the old head, ordered a new head gasket for a 4d55 engine [4d56 has 2 types] and have been running 6 months now with no problems at all. Also there are 2 types of head, one with recessed valves the other with protruding. My head was recessed. Both available in the UK.
Gasket part # available from ajusa.es online catalog. Hope this helps <img src="/forums/images/graemlins/cheers.gif" alt="" />