Finally got a funtioning fuel system. A little background: when I picked up the truck, it's batteries were dead. Known problem and was prepared for it. The station guys had the truck jumped and ready to be test driven. After the test drive, I shut it down to do a leak check, none found. Jump started it again, loaded up the pickup with the extras and off we went. When we got home, I parked the truck out of the way and started tinkering with it between other chores. After replacing the batteries, it always started. I started a PM by draining the primary filter of anny possible water. Nothing came out. I pulled the filter bowl and the filter was black; no fuel was getting to the bottom of the bowl. Same thing with the secondaries. So, I replaced the filters and wen't looking for the problem. The primary tank's fuel was black. Using a large pair of chem bio gloves (great for protecting ones hands from chemicals, liquid or otherwise) I stuck my hand down in the tank. Someone had been using the tank to dispose of their waste unfiltered, highly contaminated (dug a chunk of asphalt out of the tank) motor oil. I'm i the process of getting it filtered but that's another story. Anyway, drained the tank, pulled it off by sliding it off the rails and onto my garden trailer (sides drop down type, very handy...). Into the barn it went, where I hoisted it up with the engine hoist and some 5K cargo straps. Got the BFAW (Big Freaking Allen Wrench) and removed the drain plug. Lots of black gooey crap came out followed by black colored fuel. Then the pump assembly came out and the fuel cap and screen. A thick layer of goop was still stuck to the bottom, with chunks. One of the chunks turned out to be a 50 cent piece sized chunk of ashpalt. After much cleaning, I got most of the oil out. Enough to say the filters can function properly. I'll be doing 2 or 3 more filter changes fairly quickly to get the last of the gack out of the tank. Now comes the bad part, the pump wasn't working. In fact, it never was working. I have no idea how I made it 60 miles from there to home and started it a number of times without the pump working. Couldn't get the pump replaced (Dang, they're expensive!) so I went to the local NAPA parts store to see what the had. They had a 24 volt DC inline fuel pump, so I gave it a try. It weren't easy but i got it to work. All it has to do is last long enough to get me to and from the scrap yard so I can get rid of that tank. Truck starts right up now. There seems to be an air leak (maybe) cause it keeps surging between 10 and 15 hundred RPM. Occasionally it'll stabilize at about 850 but not for long. I'm still chasing loose lines, leaking hoses etc. so it's a work in progress. Pictures attached of the new and improved fuel system.