If I was using my truck as a frequent driver, I would convert everything over to run Ethanol gas. For a Sunday or occasional drive, car show etc., I would keep it stock and run non-Ethanol. Drain tank afterwards if I was forced to run Ethanol.
Sealing a tank properly means stripping down to bare metal, flush, apply neutralizer, flush, then heat dry quickly before the rust begins. Once completely dry, apply sealer. Applying sealer over crud may not work if the crud frees it's bond with the metal. Then it may fall and stop-up the fuel tank outlet.
Now it's time to have fun.
When Jerry's (Hotrod Lincoln's) "tank crud cleaner" is finished, he would install an in-line fuel filter, after the tank, and another filter after the fuel pump. He knows that a tiny piece of tank crud (and probably gravel dust) is lurking around for a chance to ruin his nice carburetor rebuild. The nice filters will catch it all. Fast forward 5 years, Jerry's truck starts running bad. He begins troubleshooting and would probably do the easy checks first. If nothing obvious he would eventually check fuel flow. Oh my! Not enough fuel. A fuel filter is blinded from tank crud. I can replace it and problem solved.
Now use me as the "dumb mechanic". I, like many others, would replace spark plugs, ignition points, fuel pump, do the carburetor again then question an engine rebuild. The last thing I would check is...you got it....fuel filters.
Now to be serious again.
Even with dual filters, very fine particles from a rusty tank will make it through both, to your carburetor fuel bowl (picture). It's scary.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
