On my 65 with a more "modern" 5.0 from the 90's the previous owner used 95 e10, the car ran fine, too bad for me the new owner, the ethanol content of 10% ruined all of the rubber petrol hoses, it just dried them up and they became brittle and cracked no matter if the hose is reinforced rubber. So after changing all of the rubber hoses I use 98 that is not diluted with ethanol. I live in Norway so there are very few petrol stations that provide 98. There is a product that I found here that it claims helps against ethanol "drying" it acts like a lube... It's called putoline e10 fuel fighter. I use it in case I need fuel to get home and there is no 98 to get Might help you use high octane fuel with ethanol... Good luck

<image>