Finally being able to get the fuel trims makes it obvious what I originally posted is not the issue. If it's been over compensating the fuel,I now know how the plugs got to looking that way. I'm mostly certain it's not the MAF due to having tried multiple, new and off of a working vehicle. Even though I've replaced all vacuum lines, took the intake manifold down to the heads to assure everything was sealed and have done spray test for vacuum leak, I haven't done a smoke test so I'm thinking that would be my next best step to take. Any other input from those of you that are knowledgeable on troubleshooting?

I've never had any issues with fixing the mechanical side of the known problem, it's the troubleshooting that I'd like to gain more knowledge on.