In a pinch and only in a pinch I use store bought (black bottle 104) with a real lead additive. I have been told that Marvels mystery oil is good for keeping your valves happy but have not tried yet (anybody have?). But for more GPM (grins per mile) I run a blend of 93 and 110 race fuel. My GTO club has a fuel finder on its site. I personally go to the track and buy cans of it. There is no need to run strait 110, its a whaste. you want to run enough to stop pre-ignition.
I usually run 4 to 1 (93 to 110) and it runs and smells like a champ. Unless you are driving this car all the time, there is no need for a big 55 gal drum. Ten gallons on hand, will give you 50 gallons of useable fuel.