There are plenty of flex fuel vehicles so I'm sure a standard engine would be happy on e85 with a jet change and new rubber fuel hoses, assuming the pump is big enough and compatible.

The thing about lining tanks and metal fuel lines that I've read is soft metals like zinc, aluminium, lead corrode as the ethanol dissolves the oxide layer. The concern is a little extra water in the fuel. My feeling is in a dry climate where the car lives inside or the fuel is consumed and replaced regularly metal corrosion is probably less of an issue.

Since I don't drive mine much and am going efi I figure the right materials in the fuel lines/ tank will be cheaper than replacing 8 injectors. With a carb you could probably just see how it goes.

I had a look today and the tank sheet appears to be about 1.2-1.4mm thick. drained and drying in the sun.