Yes, and I have since run the tank to about 1/2 and refilled with 93, hoping for a ~89 blend. As I drive that down, I will keep up with the 93 until I'm sure it all that is in the tank. In general: 87, 89 and 93 are commonly available with 10% ethanol. There are a few exceptions, like California and in the mountains. 100 octane is occasionally available, usually close to a race track. There was one place in Atlanta, in the middle of a suburb strangely enough. and (illegally) av gas can be found at small airstrips. But then you run into tax issues if you're caught. Non ethanol blends are available, you have to hunt them down. There are 2 here in town and I'm aiming for them on my next refuel. I am hoping to build it for an 89 octane diet. The factory compression is listed as 10.5:1 and I'm told that was often over stated. I'd like to see 9.5 or 9:1. I haven't messed with the carb at all. It runs now and carburettors are something I don't really know anything about. That will, of course, change over the winter. But that relationship between mixture and timing, carbs and distributors.....Well that's sort of the point of doing all this. The ZDDP additive isn't an additive for anything other then lubricating the flat tappets. It's to replace the zinc that the engines were designed to use, which was removed in the late '80s due to catalytic converters. I agree with you on the other additives, I was very careful about letting it idle a long time and listening for any indication of a problem. I'm always very skeptical of claims made by additives for oil or fuel. The only exceptions are fuel stabilisers for my lawn mower and the zinc to keep older engines from excessive wear.