Ethanol

Upgrade all your fuel hoses to the more expensive "fuel injection" type. It is more ethanol resistant, plus stiffer so won't collapse under vacuum. When ethanol first started being added in the late 80's, we were hassled on a cross-country trip in our 69 Dart. It would sometimes miss >55 mph or going uphill. OK in evening and worse as we hit NM (around Memorial Day). At a lunch stop, I checked and found the fuel pump inlet soft and collapsing at the bend. Replaced it and no more problems.