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I'm not really familiar with the 2.8, so there may be some common quirk that needs to be addressed. I'm sure one of the many V6 gurus here can jump in with some specifics to look for. However, in general for an issue like this, I would start by checking the fuel system and the spark. A quick check of the fuel system would be to spray some starter fluid into the intake and turn the engine over. If it starts, then there is a good chance you are having a fuel issue. In that case, you should hook up a fuel pressure gauge and see if it is building full pressure when you turn the key on. If the starter fluid didn't help it start, then it's more likely a spark issue. You can pull a spark plug, check for wear and then ground the threads to the engine block while someone turns it over again. If you don't see a strong spark then you'll need to check the ignition system closely.
Edit: make sure you don't start just putting in a bunch of new parts without knowing what the problem is. It's not uncommon to get new parts that have sat on a shelf for such a long time that they come to you DOA (i.e. broken). You can suddenly introduce additional issues without realizing it, and it makes diagnosing the initial problem much harder. Suddenly you have two faults instead of one.
[This message has been edited by Neils88 (edited 03-28-2019).]