he did a zetec in that thread, so yes, its gonna be just as much work. while there are a lot of things that are shared between the 2 motors, there is still ALOT that has to be changed to put in a zetec. ECU, wiring harnesees, engine mounjts, tranny,and various other bits
and honestly it isnt enough of an upgrade to warrant all that work, id just slap a turbo on the SPI, get it tuned, and roll with it, youll be taking any N/A zetec out there. and poss a few F/I zetecs too depepnding on your set-up.