I can't get my truck to run!

[jayoldschool]

Back story: when I bought my truck, the original rusted out tank was thrown in the back of the bed. I got the owner to get it running by strapping a temp tank in the engine bay for the pump to pull from directly. I installed a brand new tank and sender. I has a few 20L cans poured in it, the dash gauge reads 1/2 full. Gauge is working, I just put in 20L, and the gauge went up.

I did have it running and moving on the temp can, and it did run, once, for a lap around the block, on the new tank.

I can get the truck to start by priming the carb directly with a little shot of gas. It will not stay running after the initial catch, however. I replaced the rubber line that goes from the hardline on the frame rail to the pump. No difference. After trying to start, I pulled that line off, it was full of fuel, so the pump is working, it's pulling fuel.

Moved on to the carb. Put a line wrench on, got the line off fine. Pulled the filter. Filter was the bronze one, but was backwards. Cone and spring towards the carb, not the line. I could blow air through it easily. In the bottom of the filter housing, there was a build up of black grainy stuff. Dirt? Old rubber? Not sure. Blew it out with brake cleaner. Put the filter back in, cone towards the line, but I now think I put the spring in on the wrong side, I put it in the cone. I'm thinking it should go behind, pushing the filter towards the line.

Just thinking out loud. Here are things that I am considering:
- replace any other rubber line (under cab, the other section that comes out of the pump)
- replace the pump (I have a NOS spare carter here somewhere)
- add a larger filter before the carb
- rebuild the carb, it's probably full of that black crap

I welcome any and all ideas. I'm sure I'm missing something. Old cars are usually easy to get started!