I recently had to replace the original ( short - 8 inches or so )
connections from a 73 Buick LeSabre fuel tank to it's fuel delivery/return lines.
Why?

This was a near perfect 44,000 mile car with a 455 & turbo 400.
It came from rural WIsconsin where they sell "real" gasoline.

After 3 tankfuls of Illinois "re-formulated" ethanol based fuel the insides of these
short rubber hoses turned into black bubblegum. Think of what it
does to delicate carb and fuel pump parts after a while .... regardless of how old it is......

I'm Using the newer "anti phasing" stuff ( like "Stabil, but for ethanol fuel only) now.
Apparently, it prevents the fuel from separating into 3 parts ( gasoline, water, ethanol) after it passes 90 or so days. After it separates it cannot "go back" to it's
originally delivered state and will ensure that your old truck will sputter and die at some point....

This whole fuel issue is biting old car guys badly and now they want to go to 15%!
mike