Here is today's truck progress:
I am going to reuse my vent lines from my 1972 truck and they were full of rust! This "Krud Cutter" is essentially phosphoric acid, which reacts with iron oxide (rust). I used the small funnel to push the air out and once I saw product coming out the distal end, I plugged the hole with an old ink pen and clamped it shut. I'll let this sit about an hour and then rinse with distilled water (which is overkill, I know).
It worked wonders with the other parts of the vent line and this is the last piece.
Tomorrow the fuel tank will go back in.