I also have the same question on fuel, plus what type of oil to use, and what is best for storage.

Original 400 Motor (68)

I have mainly used 87 octane fuel and have had no issues. I have been told to use super octane (highest level available at stations) but I often forget that I should be doing that, thus I don't put it in the tank. Now that I have read this topic, I will become more diligent and put the highest rated octane available at the pump into the tank.

Regarding engine oil: Is it best to use the manufacturers spec's for oil grade or is there something that works better?

Regarding storage: My car gets stored for the winter (I'm in Canada) from October to April. Is there anything specific I should be doing to store it. I usually don't do anything other than drive it to the storage facility, park it, and disconnect the battery. The storage facility is indoors and heated to a temp that is moderately cool, about 50'F.