UPDATE: Ok, so I found fuel coming out of the vacuum line so I figured it MUST be a faulty diaphram... must of ruined it when I took it apart. So I did a little surgery: I COMPLETELY removed the diaphram block, made a makeshift shield/gasket and screwed the back plate directly onto the main valve body without the diaphram block. The shield basically eliminated the whole vacuum system. Then I plugged the vacuum hose at the carb to stop suction. Turned the petcock to 'on'. Now the fuel system pretty much should have an unrestricted, constant flow of fuel. I started her up and WAM, like a kitten. Inspected the valve area, not a drop of fuel. So far so good. Gave her a few revs and she responded right on the mark. I put the seat back on and took her for a few spins around the block. Boy did she RUN!!! I could almost hear her gulping up that gas. I think she ran even better than before. THEN..... about five minutes later, just as I turned around to head back home she started sputtering on me, like one cylinder wasn't responding or something. I noticed in my previous attempts that it always did the same thing. Idled great for about five minutes then the RPMS would drop suddenly and she would ultimately die. I opened the gas tank to make sure it wasn't vacuum lock and it wasn't. I'm still concerned about the 2 filters' fuel levels being so different.
A little backstory: This whole ordeal began when I removed my rusted tank to clean it out. Did the old nuts and bolts shaking thing but it only helped a little bit. When I reassembled and ran her it was a mess. I figure some debris must have gotten in the system, thus the installation of the in-line filters. I drained the bowls and injected gumout. Left it like that overnight and then installed the fuel filters and cleaned the petcock. That brought me to where this post starts.
I feel I'm so close. After all, this last test-drive was PERFECT up until the sudden loss of power. I'll keep digging. Any ideas would be much appreciated. Thanks.