I have to believe at this point that it would be much cheaper to bring it back to life that it would be to design a new engine. They were so far along with development I can't see any way, other than emissions compliance problems, that the 4.5 won't happen if they come out with a half-ton diesel. With GM playing follow the leader behind Ford, they will have to come out with a Diesel 1/2 ton. Ford could put lipstick on a pig and people would love it. Their marketing office is so far ahead of the game than the other manufacturers that it's starting to look silly at what they can get away with. How many people did not by the Cummins because it is in a Nissan? Likewise with the Ecodiesel because it is in a Dodge? The Ecodiesel did bring dodge a little closer to the top but anyone that goes on an Ecodiesel forum POLL Catastrophic Failures
would probably shy away from buying one if they didn't already have one. A diesel in an F-150, now that will outsell both the Nissan and the Dodge offering combined and possibly have Ford dropping some of their other engine options due to lake of sales with them.