I ran to the parts store this morning and grabbed a couple of $2.80 fuel filters. The clear ones come with an extra filter insert for $10. Think I'll stick to the biggies for now.
And the filter was definitely needed. The old one was clogged with crud and liquified rust. But the small filter in the carb is still pretty clean, so the primary filter is doing it's job. Lesson learned. Truck has gas, won't stay running, check the fuel filter.
The rust does not surprise me. But it's source might. I assume there is some rust in the tank. It is not leaking, but it did sit with gas in it for 12 years. Also I bought some rubber fuel hose, to replace the hose from under the cab floor to the steel line on the frame. While I was swapping the lines, some gas spilled out of the tank. It was clear and not rusty.
Could that mean there isn't rust in the tank? Dunno. And if the tank is not rusty, then I guess it is coming from the steel line between the new rubber hose and the new fuel filter.
Either way, I spilled some gas on my chest and arms while I was tightening up the new hose. The gas burned like crud, so after a quick shower and a test drive to the end of the block and back, I called it a successful day of truck repair.