Trouble starting my 4.8 (again)

[yossarian19]

I had it running a few months back & it was fine, started up a little slow but it started. Then I had to get a little "cleaner" with the wiring, re wired it (again) and now no start.
Yesterday I tried to run it and found that after too much cranking the cylinders were gas-washed (based on lack of compression noise).
Today, I pulled the plugs and all 8 were fuel fouled to some degree. Cleaned the plugs with a brass brush & brake clean, put a few squirts of oil into each cylinder, pulled the fuel relay & spun the engine over a few times. Compression was / is restored. Ate lunch, went out, installed relays & tried to jump start it. No joy - but plenty of oil smoke. Confirmed spark on the front two cylinders of the driver's bank & decided to let the starter cool down.
So, I've got fuel & I've got spark and compression sounds good. Still no fire. I think I may have gone too heavy on the oil? Not sure if that would stop it from running but I don't know what else to think just now. Any ideas?
Always possible it's something like "bad MAF" or "gunked IAC", but don't want to throw parts at it blindly.