Mate I can see that you have changed every thing, but did you test the outputs, eg, what is the map frequency when the engine is idling, what is the manifold vacuum with the engine running, what is the fuel pressure, what is the o2 signal voltage, I would assume it would be stuck on 1 volt, all this information will point you in the right direction to where the problem will be. On a good engine with good compression, valve and ignition timing right at idle hot engine, you will see around 100 hertz on the map, 20 in hg on your vacuum gauge, o2 will be cycling between .1 and .9 of a volt, coolant temp signal around .9 of a volt iat around 2.5 volts, fuel pressure around 36 psi, pulse width on the injectors around 4ms, Even if the engine had vacuum leaks, and only ran on four cyls, it would still rev with the throttle open. Manifold vacuum plays an important role on that engine if it is low the map sensor frequency will be high and that is probably why your plugs are so sooty, connect up a vacuum gauge and see what the manifold vacuum is, my guess around 10 in hg.