Pheww this was a long thread.
So we can summarize the Mazda MPV 3L duratec is probably the best option for a full swap and that we should be using the returnless 2.5 LIM with SVT dual honed 2.5 upper but to mate them we need some ingenuity.
Can we elaborate (pictures?) on the 'ingenuity' required to make the returnless LIM mate to the 3L oval port heads and also get some fuel spraying on the secondary valve?
Also which models do not have the alternator boss that has to be cut on other models? (MPV does NOT correct?)
Maybe we could put together a 3L swap guideline for starting with a taurus, escape, MPV, etc?